21515450025553 has 8 divisors (see below), whose sum is σ = 23471444201760. Its totient is φ = 19559463211680.

The previous prime is 21515450025539. The next prime is 21515450025569. The reversal of 21515450025553 is 35552005451512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21515450025553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21515450025523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5565526 + ... + 8602672.

It is an arithmetic number, because the mean of its divisors is an integer number (2933930525220).

Almost surely, 2^{21515450025553} is an apocalyptic number.

It is an amenable number.

21515450025553 is a deficient number, since it is larger than the sum of its proper divisors (1955994176207).

21515450025553 is a wasteful number, since it uses less digits than its factorization.

21515450025553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3681167.

The product of its (nonzero) digits is 750000, while the sum is 43.

The spelling of 21515450025553 in words is "twenty-one trillion, five hundred fifteen billion, four hundred fifty million, twenty-five thousand, five hundred fifty-three".