20930400 has 360 divisors, whose sum is σ = 85072680. Its totient is φ = 4976640.

The previous prime is 20930387. The next prime is 20930401. The reversal of 20930400 is 403902.

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20930401) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 1101591 + ... + 1101609.

It is an arithmetic number, because the mean of its divisors is an integer number (236313).

Almost surely, 2^20930400 is an apocalyptic number.

20930400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20930400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42536340).

20930400 is an abundant number, since it is smaller than the sum of its proper divisors (64142280).

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

20930400 is a wasteful number, since it uses less digits than its factorization.

20930400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68 (or 46 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 20930400 is about 4574.9754097700. The cubic root of 20930400 is about 275.5872848575.

The spelling of 20930400 in words is "twenty million, nine hundred thirty thousand, four hundred".