21702337056 has 72 divisors (see below), whose sum is σ = 64399345920. Its totient is φ = 6919583616.

The previous prime is 21702337051. The next prime is 21702337061. The reversal of 21702337056 is 65073320712.

21702337056 is a `hidden beast` number, since 217 + 0 + 23 + 370 + 56 = 666.

It is an interprime number because it is at equal distance from previous prime (21702337051) and next prime (21702337061).

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21702337056.

It is not an unprimeable number, because it can be changed into a prime (21702337051) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1631536 + ... + 1644783.

It is an arithmetic number, because the mean of its divisors is an integer number (894435360).

Almost surely, 2^21702337056 is an apocalyptic number.

It is an amenable number.

21702337056 is an abundant number, since it is smaller than the sum of its proper divisors (42697008864).

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

21702337056 is a wasteful number, since it uses less digits than its factorization.

21702337056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3276358 (or 3276347 counting only the distinct ones).

The product of its (nonzero) digits is 52920, while the sum is 36.

Adding to 21702337056 its reverse (65073320712), we get a palindrome (86775657768).

The spelling of 21702337056 in words is "twenty-one billion, seven hundred two million, three hundred thirty-seven thousand, fifty-six".