21249944511 has 16 divisors (see below), whose sum is σ = 29254333440. Its totient is φ = 13706314560.

The previous prime is 21249944483. The next prime is 21249944519. The reversal of 21249944511 is 11544994212.

It is not a de Polignac number, because 21249944511 - 2¹⁰ = 21249943487 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21249944519) 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, 391435 + ... + 442403.

It is an arithmetic number, because the mean of its divisors is an integer number (1828395840).

Almost surely, 2^21249944511 is an apocalyptic number.

21249944511 is a deficient number, since it is larger than the sum of its proper divisors (8004388929).

21249944511 is a wasteful number, since it uses less digits than its factorization.

21249944511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55486.

The product of its digits is 103680, while the sum is 42.

The spelling of 21249944511 in words is "twenty-one billion, two hundred forty-nine million, nine hundred forty-four thousand, five hundred eleven".