21008030400 has 1176 divisors, whose sum is σ = 92534744064. Its totient is φ = 4590950400.

The previous prime is 21008030387. The next prime is 21008030411. The reversal of 21008030400 is 403080012.

It is a happy number.

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

It is an unprimeable number.

It is a polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 253108759 + ... + 253108841.

Almost surely, 2^21008030400 is an apocalyptic number.

21008030400 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 21008030400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46267372032).

21008030400 is an abundant number, since it is smaller than the sum of its proper divisors (71526713664).

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

21008030400 is an equidigital number, since it uses as much as digits as its factorization.

21008030400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The spelling of 21008030400 in words is "twenty-one billion, eight million, thirty thousand, four hundred".