20401320400 has 30 divisors (see below), whose sum is σ = 49014173222. Its totient is φ = 8160528000.

The previous prime is 20401320397. The next prime is 20401320419. The reversal of 20401320400 is 402310402.

It can be written as a sum of positive squares in 3 ways, for example, as 2623898176 + 17777422224 = 51224^2 + 133332^2 .

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 25501251 + ... + 25502050.

Almost surely, 2^20401320400 is an apocalyptic number.

20401320400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20401320400 is an abundant number, since it is smaller than the sum of its proper divisors (28612852822).

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

20401320400 is a wasteful number, since it uses less digits than its factorization.

20401320400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51003319 (or 51003308 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

Adding to 20401320400 its reverse (402310402), we get a palindrome (20803630802).

The spelling of 20401320400 in words is "twenty billion, four hundred one million, three hundred twenty thousand, four hundred".