21640930734 has 8 divisors (see below), whose sum is σ = 43281861480. Its totient is φ = 7213643576.

The previous prime is 21640930643. The next prime is 21640930747. The reversal of 21640930734 is 43703904612.

It is a sphenic number, since it is the product of 3 distinct primes.

21640930734 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21640930692 and 21640930701.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1803410889 + ... + 1803410900.

It is an arithmetic number, because the mean of its divisors is an integer number (5410232685).

Almost surely, 2^21640930734 is an apocalyptic number.

21640930734 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21640930734 is a wasteful number, since it uses less digits than its factorization.

21640930734 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3606821794.

The product of its (nonzero) digits is 108864, while the sum is 39.

The spelling of 21640930734 in words is "twenty-one billion, six hundred forty million, nine hundred thirty thousand, seven hundred thirty-four".