21090700400 has 240 divisors, whose sum is σ = 63576192768. Its totient is φ = 6531840000.

The previous prime is 21090700357. The next prime is 21090700417. The reversal of 21090700400 is 400709012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5018300 + ... + 5022500.

Almost surely, 2^21090700400 is an apocalyptic number.

21090700400 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 21090700400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31788096384).

21090700400 is an abundant number, since it is smaller than the sum of its proper divisors (42485492368).

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

21090700400 is a wasteful number, since it uses less digits than its factorization.

21090700400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4400 (or 4389 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 23.

The spelling of 21090700400 in words is "twenty-one billion, ninety million, seven hundred thousand, four hundred".