20981475 has 18 divisors (see below), whose sum is σ = 37580556. Its totient is φ = 11190000.

The previous prime is 20981473. The next prime is 20981507. The reversal of 20981475 is 57418902.

It is not a de Polignac number, because 20981475 - 2¹ = 20981473 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (20981473) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 46401 + ... + 46850.

Almost surely, 2^20981475 is an apocalyptic number.

20981475 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20981475 is a deficient number, since it is larger than the sum of its proper divisors (16599081).

20981475 is a wasteful number, since it uses less digits than its factorization.

20981475 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93267 (or 93259 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 20981475 is about 4580.5540057945. The cubic root of 20981475 is about 275.8112682631.

The spelling of 20981475 in words is "twenty million, nine hundred eighty-one thousand, four hundred seventy-five".