21250374885 has 12 divisors (see below), whose sum is σ = 36833983212. Its totient is φ = 11333533248.

The previous prime is 21250374881. The next prime is 21250374941. The reversal of 21250374885 is 58847305212.

21250374885 is a `hidden beast` number, since 21 + 2 + 503 + 7 + 48 + 85 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 8250270561 + 13000104324 = 90831^2 + 114018^2 .

It is not a de Polignac number, because 21250374885 - 2² = 21250374881 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 472230553 = 21250374885 / (2 + 1 + 2 + 5 + 0 + 3 + 7 + 4 + 8 + 8 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 21250374885.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21250374881) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 236115232 + ... + 236115321.

It is an arithmetic number, because the mean of its divisors is an integer number (3069498601).

Almost surely, 2^21250374885 is an apocalyptic number.

It is an amenable number.

21250374885 is a deficient number, since it is larger than the sum of its proper divisors (15583608327).

21250374885 is a wasteful number, since it uses less digits than its factorization.

21250374885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472230564 (or 472230561 counting only the distinct ones).

The product of its (nonzero) digits is 537600, while the sum is 45.

The spelling of 21250374885 in words is "twenty-one billion, two hundred fifty million, three hundred seventy-four thousand, eight hundred eighty-five".