20397552400 has 135 divisors (see below), whose sum is σ = 50627691261. Its totient is φ = 7897374720.

The previous prime is 20397552389. The next prime is 20397552403. The reversal of 20397552400 is 425579302.

The square root of 20397552400 is 142820.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 13 ways, for example, as 9333878544 + 11063673856 = 96612^2 + 105184^2 .

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20397552400.

It is not an unprimeable number, because it can be changed into a prime (20397552403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 105686704 + ... + 105686896.

Almost surely, 2^20397552400 is an apocalyptic number.

20397552400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

20397552400 is the 142820-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20397552400

20397552400 is an abundant number, since it is smaller than the sum of its proper divisors (30230138861).

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

20397552400 is an equidigital number, since it uses as much as digits as its factorization.

20397552400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478 (or 237 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 37.

The spelling of 20397552400 in words is "twenty billion, three hundred ninety-seven million, five hundred fifty-two thousand, four hundred".