2157820344 has 128 divisors (see below), whose sum is σ = 6122376000. Its totient is φ = 703987200.

The previous prime is 2157820339. The next prime is 2157820349. The reversal of 2157820344 is 4430287512.

It is a happy number.

2157820344 is a `hidden beast` number, since 21 + 578 + 20 + 3 + 44 = 666.

It is an interprime number because it is at equal distance from previous prime (2157820339) and next prime (2157820349).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 2157820299 and 2157820308.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157820349) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5125254 + ... + 5125674.

Almost surely, 2^2157820344 is an apocalyptic number.

2157820344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2157820344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3061188000).

2157820344 is an abundant number, since it is smaller than the sum of its proper divisors (3964555656).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2157820344 is a wasteful number, since it uses less digits than its factorization.

2157820344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 886 (or 876 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The square root of 2157820344 is about 46452.3448708459. The cubic root of 2157820344 is about 1292.2258596730.

The spelling of 2157820344 in words is "two billion, one hundred fifty-seven million, eight hundred twenty thousand, three hundred forty-four".