20973940 has 24 divisors (see below), whose sum is σ = 47433960. Its totient is φ = 7744128.

The previous prime is 20973913. The next prime is 20973943. The reversal of 20973940 is 4937902.

It can be written as a sum of positive squares in 4 ways, for example, as 70756 + 20903184 = 266^2 + 4572^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20973896 and 20973905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20973943) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40075 + ... + 40594.

It is an arithmetic number, because the mean of its divisors is an integer number (1976415).

Almost surely, 2^20973940 is an apocalyptic number.

20973940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20973940 is an abundant number, since it is smaller than the sum of its proper divisors (26460020).

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

20973940 is a wasteful number, since it uses less digits than its factorization.

20973940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80691 (or 80689 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 34.

The square root of 20973940 is about 4579.7314331738. The cubic root of 20973940 is about 275.7782472809.

The spelling of 20973940 in words is "twenty million, nine hundred seventy-three thousand, nine hundred forty".