21515001554402 has 16 divisors (see below), whose sum is σ = 32292155647872. Its totient is φ = 10750951670160.

The previous prime is 21515001554363. The next prime is 21515001554407. The reversal of 21515001554402 is 20445510051512.

It is not an unprimeable number, because it can be changed into a prime (21515001554407) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21179033 + ... + 22171635.

It is an arithmetic number, because the mean of its divisors is an integer number (2018259727992).

Almost surely, 2^{21515001554402} is an apocalyptic number.

21515001554402 is a deficient number, since it is larger than the sum of its proper divisors (10777154093470).

21515001554402 is a wasteful number, since it uses less digits than its factorization.

21515001554402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 999193.

The product of its (nonzero) digits is 40000, while the sum is 35.

The spelling of 21515001554402 in words is "twenty-one trillion, five hundred fifteen billion, one million, five hundred fifty-four thousand, four hundred two".