21877765445 has 16 divisors (see below), whose sum is σ = 27204510960. Its totient is φ = 16870124544.

The previous prime is 21877765423. The next prime is 21877765451. The reversal of 21877765445 is 54456777812.

It can be written as a sum of positive squares in 8 ways, for example, as 1445064196 + 20432701249 = 38014^2 + 142943^2 .

It is a cyclic number.

It is not a de Polignac number, because 21877765445 - 2²⁴ = 21860988229 is a prime.

It is a Curzon number.

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, 41234 + ... + 213203.

It is an arithmetic number, because the mean of its divisors is an integer number (1700281935).

Almost surely, 2^21877765445 is an apocalyptic number.

It is an amenable number.

21877765445 is a deficient number, since it is larger than the sum of its proper divisors (5326745515).

21877765445 is a wasteful number, since it uses less digits than its factorization.

21877765445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255064.

The product of its digits is 13171200, while the sum is 56.

The spelling of 21877765445 in words is "twenty-one billion, eight hundred seventy-seven million, seven hundred sixty-five thousand, four hundred forty-five".