21640215536502 has 48 divisors (see below), whose sum is σ = 44040078742080. Its totient is φ = 7088945911344.

The previous prime is 21640215536491. The next prime is 21640215536573. The reversal of 21640215536502 is 20563551204612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 67908513 + ... + 68226435.

It is an arithmetic number, because the mean of its divisors is an integer number (917501640460).

Almost surely, 2^{21640215536502} is an apocalyptic number.

21640215536502 is an abundant number, since it is smaller than the sum of its proper divisors (22399863205578).

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

21640215536502 is a wasteful number, since it uses less digits than its factorization.

21640215536502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321305 (or 321246 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 42.

The spelling of 21640215536502 in words is "twenty-one trillion, six hundred forty billion, two hundred fifteen million, five hundred thirty-six thousand, five hundred two".