21365507472445 has 16 divisors (see below), whose sum is σ = 26000793365760. Its totient is φ = 16852365880000.

The previous prime is 21365507472433. The next prime is 21365507472461. The reversal of 21365507472445 is 54427470556312.

It is not a de Polignac number, because 21365507472445 - 2²¹ = 21365505375293 is a prime.

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, 88389631 + ... + 88631020.

It is an arithmetic number, because the mean of its divisors is an integer number (1625049585360).

Almost surely, 2^{21365507472445} is an apocalyptic number.

It is an amenable number.

21365507472445 is a deficient number, since it is larger than the sum of its proper divisors (4635285893315).

21365507472445 is a wasteful number, since it uses less digits than its factorization.

21365507472445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177020996.

The product of its (nonzero) digits is 28224000, while the sum is 55.

The spelling of 21365507472445 in words is "twenty-one trillion, three hundred sixty-five billion, five hundred seven million, four hundred seventy-two thousand, four hundred forty-five".