20420660 has 24 divisors (see below), whose sum is σ = 46182696. Its totient is φ = 7539840.

The previous prime is 20420651. The next prime is 20420681. The reversal of 20420660 is 6602402.

It can be written as a sum of positive squares in 4 ways, for example, as 2085136 + 18335524 = 1444^2 + 4282^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39011 + ... + 39530.

It is an arithmetic number, because the mean of its divisors is an integer number (1924279).

Almost surely, 2^20420660 is an apocalyptic number.

20420660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20420660 is an abundant number, since it is smaller than the sum of its proper divisors (25762036).

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

20420660 is a wasteful number, since it uses less digits than its factorization.

20420660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78563 (or 78561 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 20420660 is about 4518.9224379270. The cubic root of 20420660 is about 273.3316511232.

The spelling of 20420660 in words is "twenty million, four hundred twenty thousand, six hundred sixty".