21645152358 has 16 divisors (see below), whose sum is σ = 43373401776. Its totient is φ = 7201201280.

The previous prime is 21645152357. The next prime is 21645152359. The reversal of 21645152358 is 85325154612.

It is an interprime number because it is at equal distance from previous prime (21645152357) and next prime (21645152359).

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21645152357) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3458991 + ... + 3465242.

It is an arithmetic number, because the mean of its divisors is an integer number (2710837611).

Almost surely, 2^21645152358 is an apocalyptic number.

21645152358 is an abundant number, since it is smaller than the sum of its proper divisors (21728249418).

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

21645152358 is a wasteful number, since it uses less digits than its factorization.

21645152358 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6924759.

The product of its digits is 288000, while the sum is 42.

The spelling of 21645152358 in words is "twenty-one billion, six hundred forty-five million, one hundred fifty-two thousand, three hundred fifty-eight".