20400036 has 24 divisors (see below), whose sum is σ = 47816160. Its totient is φ = 6769152.

The previous prime is 20400031. The next prime is 20400049. The reversal of 20400036 is 63000402.

It is a super-2 number, since 2×20400036² = 832322937602592, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20399988 and 20400024.

It is not an unprimeable number, because it can be changed into a prime (20400031) 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 7 ways as a sum of consecutive naturals, for example, 1021 + ... + 6468.

It is an arithmetic number, because the mean of its divisors is an integer number (1992340).

Almost surely, 2^20400036 is an apocalyptic number.

It is an amenable number.

20400036 is an abundant number, since it is smaller than the sum of its proper divisors (27416124).

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

20400036 is a wasteful number, since it uses less digits than its factorization.

20400036 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7723 (or 7721 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 20400036 is about 4516.6399015197. The cubic root of 20400036 is about 273.2396023384.

Adding to 20400036 its reverse (63000402), we get a palindrome (83400438).

The spelling of 20400036 in words is "twenty million, four hundred thousand, thirty-six".