21554610630697 has 2 divisors, whose sum is σ = 21554610630698. Its totient is φ = 21554610630696.

The previous prime is 21554610630617. The next prime is 21554610630727. The reversal of 21554610630697 is 79603601645512.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21520729233936 + 33881396761 = 4639044^2 + 184069^2 .

It is a cyclic number.

It is not a de Polignac number, because 21554610630697 - 2¹⁹ = 21554610106409 is a prime.

It is a super-2 number, since 2×21554610630697² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21554610630617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10777305315348 + 10777305315349.

It is an arithmetic number, because the mean of its divisors is an integer number (10777305315349).

Almost surely, 2^{21554610630697} is an apocalyptic number.

It is an amenable number.

21554610630697 is a deficient number, since it is larger than the sum of its proper divisors (1).

21554610630697 is an equidigital number, since it uses as much as digits as its factorization.

21554610630697 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8164800, while the sum is 55.

The spelling of 21554610630697 in words is "twenty-one trillion, five hundred fifty-four billion, six hundred ten million, six hundred thirty thousand, six hundred ninety-seven".