21621532563450 has 96 divisors (see below), whose sum is σ = 59662201017600. Its totient is φ = 5757722645760.

The previous prime is 21621532563431. The next prime is 21621532563479. The reversal of 21621532563450 is 5436523512612.

21621532563450 is a `hidden beast` number, since 2 + 1 + 6 + 2 + 1 + 5 + 3 + 2 + 5 + 634 + 5 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a junction number, because it is equal to n+sod(n) for n = 21621532563396 and 21621532563405.

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, 10167007 + ... + 12108306.

It is an arithmetic number, because the mean of its divisors is an integer number (621481260600).

Almost surely, 2^{21621532563450} is an apocalyptic number.

21621532563450 is an abundant number, since it is smaller than the sum of its proper divisors (38040668454150).

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

21621532563450 is a wasteful number, since it uses less digits than its factorization.

21621532563450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22276053 (or 22276042 counting only the distinct ones).

The product of its (nonzero) digits is 1296000, while the sum is 45.

The spelling of 21621532563450 in words is "twenty-one trillion, six hundred twenty-one billion, five hundred thirty-two million, five hundred sixty-three thousand, four hundred fifty".