21645654612 has 96 divisors (see below), whose sum is σ = 51979200000. Its totient is φ = 7008768000.

The previous prime is 21645654593. The next prime is 21645654619.

21645654612 is nontrivially palindromic in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21645654619) 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, 17329764 + ... + 17331012.

It is an arithmetic number, because the mean of its divisors is an integer number (541450000).

Almost surely, 2^21645654612 is an apocalyptic number.

It is an amenable number.

21645654612 is an abundant number, since it is smaller than the sum of its proper divisors (30333545388).

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

21645654612 is a wasteful number, since it uses less digits than its factorization.

21645654612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1617 (or 1615 counting only the distinct ones).

The product of its digits is 345600, while the sum is 42.

The spelling of 21645654612 in words is "twenty-one billion, six hundred forty-five million, six hundred fifty-four thousand, six hundred twelve".