21506734743512 has 64 divisors (see below), whose sum is σ = 43915382975520. Its totient is φ = 9832861513728.

The previous prime is 21506734743509. The next prime is 21506734743517. The reversal of 21506734743512 is 21534743760512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21506734743517) 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, 308018 + ... + 6565694.

Almost surely, 2^{21506734743512} is an apocalyptic number.

It is an amenable number.

21506734743512 is an abundant number, since it is smaller than the sum of its proper divisors (22408648232008).

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

21506734743512 is a wasteful number, since it uses less digits than its factorization.

21506734743512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6258420 (or 6258416 counting only the distinct ones).

The product of its (nonzero) digits is 4233600, while the sum is 50.

The spelling of 21506734743512 in words is "twenty-one trillion, five hundred six billion, seven hundred thirty-four million, seven hundred forty-three thousand, five hundred twelve".