21073770 has 40 divisors (see below), whose sum is σ = 56667204. Its totient is φ = 5619456.

The previous prime is 21073739. The next prime is 21073799. The reversal of 21073770 is 7737012.

It can be written as a sum of positive squares in 2 ways, for example, as 20985561 + 88209 = 4581^2 + 297^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 12199 + ... + 13818.

Almost surely, 2^21073770 is an apocalyptic number.

21073770 is an abundant number, since it is smaller than the sum of its proper divisors (35593434).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21073770 is a wasteful number, since it uses less digits than its factorization.

21073770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26036 (or 26027 counting only the distinct ones).

The product of its (nonzero) digits is 2058, while the sum is 27.

The square root of 21073770 is about 4590.6176055080. The cubic root of 21073770 is about 276.2150969737.

The spelling of 21073770 in words is "twenty-one million, seventy-three thousand, seven hundred seventy".