21531030250400 has 144 divisors (see below), whose sum is σ = 60714051552000. Its totient is φ = 7368908697600.

The previous prime is 21531030250309. The next prime is 21531030250409. The reversal of 21531030250400 is 405203013512.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21531030250400.

It is not an unprimeable number, because it can be changed into a prime (21531030250409) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 71812400 + ... + 72111599.

It is an arithmetic number, because the mean of its divisors is an integer number (421625358000).

Almost surely, 2^{21531030250400} is an apocalyptic number.

21531030250400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21531030250400 is an abundant number, since it is smaller than the sum of its proper divisors (39183021301600).

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

21531030250400 is a wasteful number, since it uses less digits than its factorization.

21531030250400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143924047 (or 143924034 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 26.

Adding to 21531030250400 its reverse (405203013512), we get a palindrome (21936233263912).

The spelling of 21531030250400 in words is "twenty-one trillion, five hundred thirty-one billion, thirty million, two hundred fifty thousand, four hundred".