21651065004 has 24 divisors (see below), whose sum is σ = 50728781488. Its totient is φ = 7187074560.

The previous prime is 21651064991. The next prime is 21651065011. The reversal of 21651065004 is 40056015612.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3740377 + ... + 3746160.

Almost surely, 2^21651065004 is an apocalyptic number.

It is an amenable number.

21651065004 is an abundant number, since it is smaller than the sum of its proper divisors (29077716484).

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

21651065004 is a wasteful number, since it uses less digits than its factorization.

21651065004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7486785 (or 7486783 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The spelling of 21651065004 in words is "twenty-one billion, six hundred fifty-one million, sixty-five thousand, four".