18700020 has 36 divisors (see below), whose sum is σ = 56723940. Its totient is φ = 4986624.

The previous prime is 18700013. The next prime is 18700027. The reversal of 18700020 is 2000781.

It is an interprime number because it is at equal distance from previous prime (18700013) and next prime (18700027).

It can be written as a sum of positive squares in 2 ways, for example, as 9771876 + 8928144 = 3126^2 + 2988^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 18699966 and 18700002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18700027) 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, 51765 + ... + 52124.

It is an arithmetic number, because the mean of its divisors is an integer number (1575665).

Almost surely, 2^18700020 is an apocalyptic number.

18700020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18700020 is an abundant number, since it is smaller than the sum of its proper divisors (38023920).

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

18700020 is a wasteful number, since it uses less digits than its factorization.

18700020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103904 (or 103899 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 18700020 is about 4324.3519745738. The cubic root of 18700020 is about 265.4283803544.

The spelling of 18700020 in words is "eighteen million, seven hundred thousand, twenty".