21645460158 has 64 divisors (see below), whose sum is σ = 49672465920. Its totient is φ = 6159837312.

The previous prime is 21645460157. The next prime is 21645460211. The reversal of 21645460158 is 85106454612.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21645460153) 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, 18234841 + ... + 18236027.

It is an arithmetic number, because the mean of its divisors is an integer number (776132280).

Almost surely, 2^21645460158 is an apocalyptic number.

21645460158 is an abundant number, since it is smaller than the sum of its proper divisors (28027005762).

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

21645460158 is a wasteful number, since it uses less digits than its factorization.

21645460158 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2561.

The product of its (nonzero) digits is 230400, while the sum is 42.

The spelling of 21645460158 in words is "twenty-one billion, six hundred forty-five million, four hundred sixty thousand, one hundred fifty-eight".