20678940 has 36 divisors (see below), whose sum is σ = 62726664. Its totient is φ = 5514336.

The previous prime is 20678923. The next prime is 20678951. The reversal of 20678940 is 4987602.

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 (36).

It is a junction number, because it is equal to n+sod(n) for n = 20678895 and 20678904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 57262 + ... + 57621.

Almost surely, 2^20678940 is an apocalyptic number.

20678940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20678940 is an abundant number, since it is smaller than the sum of its proper divisors (42047724).

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

20678940 is a wasteful number, since it uses less digits than its factorization.

20678940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114898 (or 114893 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 20678940 is about 4547.4102520006. The cubic root of 20678940 is about 274.4791905951.

The spelling of 20678940 in words is "twenty million, six hundred seventy-eight thousand, nine hundred forty".