21653718366 has 32 divisors (see below), whose sum is σ = 49532675328. Its totient is φ = 6181968960.

The previous prime is 21653718349. The next prime is 21653718377. The reversal of 21653718366 is 66381735612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 145455 + ... + 253898.

It is an arithmetic number, because the mean of its divisors is an integer number (1547896104).

Almost surely, 2^21653718366 is an apocalyptic number.

21653718366 is an abundant number, since it is smaller than the sum of its proper divisors (27878956962).

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

21653718366 is a wasteful number, since it uses less digits than its factorization.

21653718366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400656.

The product of its digits is 1088640, while the sum is 48.

The spelling of 21653718366 in words is "twenty-one billion, six hundred fifty-three million, seven hundred eighteen thousand, three hundred sixty-six".