21662552461553 has 2 divisors, whose sum is σ = 21662552461554. Its totient is φ = 21662552461552.

The previous prime is 21662552461549. The next prime is 21662552461633. The reversal of 21662552461553 is 35516425526612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21244936663729 + 417615797824 = 4609223^2 + 646232^2 .

It is a cyclic number.

It is not a de Polignac number, because 21662552461553 - 2² = 21662552461549 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21662552461495 and 21662552461504.

It is not a weakly prime, because it can be changed into another prime (21662554461553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10831276230776 + 10831276230777.

It is an arithmetic number, because the mean of its divisors is an integer number (10831276230777).

Almost surely, 2^{21662552461553} is an apocalyptic number.

It is an amenable number.

21662552461553 is a deficient number, since it is larger than the sum of its proper divisors (1).

21662552461553 is an equidigital number, since it uses as much as digits as its factorization.

21662552461553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12960000, while the sum is 53.

The spelling of 21662552461553 in words is "twenty-one trillion, six hundred sixty-two billion, five hundred fifty-two million, four hundred sixty-one thousand, five hundred fifty-three".