2157421573440 has 1344 divisors, whose sum is σ = 9198410457600. Its totient is φ = 470877732864.

The previous prime is 2157421573357. The next prime is 2157421573441. The reversal of 2157421573440 is 443751247512.

2157421573440 is a `hidden beast` number, since 2 + 1 + 5 + 74 + 2 + 1 + 573 + 4 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1344).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157421573441) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1531171456 + ... + 1531172864.

It is an arithmetic number, because the mean of its divisors is an integer number (6844055400).

Almost surely, 2^{2157421573440} is an apocalyptic number.

2157421573440 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 2157421573440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4599205228800).

2157421573440 is an abundant number, since it is smaller than the sum of its proper divisors (7040988884160).

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

2157421573440 is a wasteful number, since it uses less digits than its factorization.

2157421573440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1574 (or 1552 counting only the distinct ones).

The product of its (nonzero) digits is 940800, while the sum is 45.

The spelling of 2157421573440 in words is "two trillion, one hundred fifty-seven billion, four hundred twenty-one million, five hundred seventy-three thousand, four hundred forty".