21912251845 has 16 divisors (see below), whose sum is σ = 29113270848. Its totient is φ = 15698327040.

The previous prime is 21912251783. The next prime is 21912251873. The reversal of 21912251845 is 54815221912.

It is a happy number.

It is not a de Polignac number, because 21912251845 - 2⁷ = 21912251717 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21912251798 and 21912251807.

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, 2969484 + ... + 2976853.

It is an arithmetic number, because the mean of its divisors is an integer number (1819579428).

Almost surely, 2^21912251845 is an apocalyptic number.

It is an amenable number.

21912251845 is a deficient number, since it is larger than the sum of its proper divisors (7201019003).

21912251845 is a wasteful number, since it uses less digits than its factorization.

21912251845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5946420.

The product of its digits is 57600, while the sum is 40.

The spelling of 21912251845 in words is "twenty-one billion, nine hundred twelve million, two hundred fifty-one thousand, eight hundred forty-five".