21609701969156 has 48 divisors (see below), whose sum is σ = 43775590803840. Its totient is φ = 9142771008000.

The previous prime is 21609701969153. The next prime is 21609701969159. The reversal of 21609701969156 is 65196910790612.

It is an interprime number because it is at equal distance from previous prime (21609701969153) and next prime (21609701969159).

It is not an unprimeable number, because it can be changed into a prime (21609701969153) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12811151 + ... + 14399478.

It is an arithmetic number, because the mean of its divisors is an integer number (911991475080).

Almost surely, 2^{21609701969156} is an apocalyptic number.

It is an amenable number.

21609701969156 is an abundant number, since it is smaller than the sum of its proper divisors (22165888834684).

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

21609701969156 is a wasteful number, since it uses less digits than its factorization.

21609701969156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27211004 (or 27211002 counting only the distinct ones).

The product of its (nonzero) digits is 11022480, while the sum is 62.

The spelling of 21609701969156 in words is "twenty-one trillion, six hundred nine billion, seven hundred one million, nine hundred sixty-nine thousand, one hundred fifty-six".