20730400 has 36 divisors (see below), whose sum is σ = 50610042. Its totient is φ = 8291840.

The previous prime is 20730373. The next prime is 20730407. The reversal of 20730400 is 403702.

It can be written as a sum of positive squares in 3 ways, for example, as 16353936 + 4376464 = 4044^2 + 2092^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (20730407) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12157 + ... + 13756.

Almost surely, 2^20730400 is an apocalyptic number.

20730400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20730400 is an abundant number, since it is smaller than the sum of its proper divisors (29879642).

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

20730400 is a wasteful number, since it uses less digits than its factorization.

20730400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25933 (or 25920 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 16.

The square root of 20730400 is about 4553.0649017997. The cubic root of 20730400 is about 274.7066845056.

The spelling of 20730400 in words is "twenty million, seven hundred thirty thousand, four hundred".