21249490838400 has 3072 divisors, whose sum is σ = 91301642035200. Its totient is φ = 4777574400000.

The previous prime is 21249490838399. The next prime is 21249490838449. The reversal of 21249490838400 is 483809494212.

It is a happy number.

21249490838400 is a `hidden beast` number, since 21 + 2 + 494 + 90 + 8 + 3 + 8 + 40 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 110100988704 + ... + 110100988896.

It is an arithmetic number, because the mean of its divisors is an integer number (29720586600).

Almost surely, 2^{21249490838400} is an apocalyptic number.

21249490838400 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 21249490838400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45650821017600).

21249490838400 is an abundant number, since it is smaller than the sum of its proper divisors (70052151196800).

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

21249490838400 is a wasteful number, since it uses less digits than its factorization.

21249490838400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406 (or 383 counting only the distinct ones).

The product of its (nonzero) digits is 3981312, while the sum is 54.

The spelling of 21249490838400 in words is "twenty-one trillion, two hundred forty-nine billion, four hundred ninety million, eight hundred thirty-eight thousand, four hundred".