2156501340 has 384 divisors, whose sum is σ = 8347207680. Its totient is φ = 450883584.

The previous prime is 2156501339. The next prime is 2156501359. The reversal of 2156501340 is 431056512.

2156501340 is a `hidden beast` number, since 2 + 1 + 5 + 650 + 1 + 3 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2377167 + ... + 2378073.

It is an arithmetic number, because the mean of its divisors is an integer number (21737520).

Almost surely, 2^2156501340 is an apocalyptic number.

2156501340 is a gapful number since it is divisible by the number (20) 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 2156501340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4173603840).

2156501340 is an abundant number, since it is smaller than the sum of its proper divisors (6190706340).

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

2156501340 is a wasteful number, since it uses less digits than its factorization.

2156501340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 986 (or 978 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 2156501340 is about 46438.1453118016. The cubic root of 2156501340 is about 1291.9625077383.

Adding to 2156501340 its reverse (431056512), we get a palindrome (2587557852).

The spelling of 2156501340 in words is "two billion, one hundred fifty-six million, five hundred one thousand, three hundred forty".