21510904207 has 16 divisors (see below), whose sum is σ = 24391755360. Its totient is φ = 18805813632.

The previous prime is 21510904189. The next prime is 21510904229. The reversal of 21510904207 is 70240901512.

It is a cyclic number.

It is not a de Polignac number, because 21510904207 - 2¹⁵ = 21510871439 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21510904237) 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, 1040253 + ... + 1060729.

It is an arithmetic number, because the mean of its divisors is an integer number (1524484710).

Almost surely, 2^21510904207 is an apocalyptic number.

21510904207 is a deficient number, since it is larger than the sum of its proper divisors (2880851153).

21510904207 is a wasteful number, since it uses less digits than its factorization.

21510904207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24762.

The product of its (nonzero) digits is 5040, while the sum is 31.

The spelling of 21510904207 in words is "twenty-one billion, five hundred ten million, nine hundred four thousand, two hundred seven".