20992400 has 120 divisors (see below), whose sum is σ = 59412864. Its totient is φ = 7027200.

The previous prime is 20992393. The next prime is 20992403. The reversal of 20992400 is 429902.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a self number, because there is not a number n which added to its sum of digits gives 20992400.

It is not an unprimeable number, because it can be changed into a prime (20992403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 57017 + ... + 57383.

Almost surely, 2^20992400 is an apocalyptic number.

20992400 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 20992400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29706432).

20992400 is an abundant number, since it is smaller than the sum of its proper divisors (38420464).

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

20992400 is a wasteful number, since it uses less digits than its factorization.

20992400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409 (or 398 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 20992400 is about 4581.7463919340. The cubic root of 20992400 is about 275.8591313624.

The spelling of 20992400 in words is "twenty million, nine hundred ninety-two thousand, four hundred".