20178020 has 12 divisors (see below), whose sum is σ = 42373884. Its totient is φ = 8071200.

The previous prime is 20178017. The next prime is 20178043. The reversal of 20178020 is 2087102.

It can be written as a sum of positive squares in 2 ways, for example, as 6280036 + 13897984 = 2506^2 + 3728^2 .

It is a super-2 number, since 2×20178020² = 814304982240800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 1008901 = 20178020 / (2 + 0 + 1 + 7 + 8 + 0 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 20177983 and 20178001.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 504431 + ... + 504470.

It is an arithmetic number, because the mean of its divisors is an integer number (3531157).

Almost surely, 2^20178020 is an apocalyptic number.

20178020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20178020 is an abundant number, since it is smaller than the sum of its proper divisors (22195864).

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

20178020 is a wasteful number, since it uses less digits than its factorization.

20178020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1008910 (or 1008908 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 20178020 is about 4491.9951024016. The cubic root of 20178020 is about 272.2447515869.

The spelling of 20178020 in words is "twenty million, one hundred seventy-eight thousand, twenty".