20621770 has 64 divisors (see below), whose sum is σ = 42293664. Its totient is φ = 7188480.

The previous prime is 20621759. The next prime is 20621771. The reversal of 20621770 is 7712602.

It can be written as a sum of positive squares in 16 ways, for example, as 1089 + 20620681 = 33^2 + 4541^2 .

It is not an unprimeable number, because it can be changed into a prime (20621771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 282454 + ... + 282526.

Almost surely, 2^20621770 is an apocalyptic number.

20621770 is an abundant number, since it is smaller than the sum of its proper divisors (21671894).

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

20621770 is a wasteful number, since it uses less digits than its factorization.

20621770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187.

The product of its (nonzero) digits is 1176, while the sum is 25.

The square root of 20621770 is about 4541.1199059263. The cubic root of 20621770 is about 274.2260109751.

The spelling of 20621770 in words is "twenty million, six hundred twenty-one thousand, seven hundred seventy".