21197958255 has 64 divisors (see below), whose sum is σ = 38971699200. Its totient is φ = 10920977280.

The previous prime is 21197958251. The next prime is 21197958259. The reversal of 21197958255 is 55285979112.

21197958255 is a `hidden beast` number, since 2 + 1 + 1 + 9 + 7 + 9 + 582 + 55 = 666.

It is an interprime number because it is at equal distance from previous prime (21197958251) and next prime (21197958259).

It is not a de Polignac number, because 21197958255 - 2² = 21197958251 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21197958251) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2452281 + ... + 2460909.

It is an arithmetic number, because the mean of its divisors is an integer number (608932800).

Almost surely, 2^21197958255 is an apocalyptic number.

21197958255 is a deficient number, since it is larger than the sum of its proper divisors (17773740945).

21197958255 is a wasteful number, since it uses less digits than its factorization.

21197958255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9261 (or 9255 counting only the distinct ones).

The product of its digits is 2268000, while the sum is 54.

The spelling of 21197958255 in words is "twenty-one billion, one hundred ninety-seven million, nine hundred fifty-eight thousand, two hundred fifty-five".