21615645334 has 16 divisors (see below), whose sum is σ = 32629766400. Its totient is φ = 10739105064.

The previous prime is 21615645313. The next prime is 21615645343. The reversal of 21615645334 is 43354651612.

It is a super-2 number, since 2×21615645334² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1017877 + ... + 1038895.

It is an arithmetic number, because the mean of its divisors is an integer number (2039360400).

Almost surely, 2^21615645334 is an apocalyptic number.

21615645334 is a deficient number, since it is larger than the sum of its proper divisors (11014121066).

21615645334 is a wasteful number, since it uses less digits than its factorization.

21615645334 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24267.

The product of its digits is 259200, while the sum is 40.

The spelling of 21615645334 in words is "twenty-one billion, six hundred fifteen million, six hundred forty-five thousand, three hundred thirty-four".