21551503215 has 16 divisors (see below), whose sum is σ = 37617169536. Its totient is φ = 10449213600.

The previous prime is 21551503213. The next prime is 21551503219. The reversal of 21551503215 is 51230515512.

It is not a de Polignac number, because 21551503215 - 2¹ = 21551503213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21551503213) 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, 65307421 + ... + 65307750.

It is an arithmetic number, because the mean of its divisors is an integer number (2351073096).

Almost surely, 2^21551503215 is an apocalyptic number.

21551503215 is a deficient number, since it is larger than the sum of its proper divisors (16065666321).

21551503215 is a wasteful number, since it uses less digits than its factorization.

21551503215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130615190.

The product of its (nonzero) digits is 7500, while the sum is 30.

The spelling of 21551503215 in words is "twenty-one billion, five hundred fifty-one million, five hundred three thousand, two hundred fifteen".