15920661553 has 2 divisors, whose sum is σ = 15920661554. Its totient is φ = 15920661552.

The previous prime is 15920661527. The next prime is 15920661557. The reversal of 15920661553 is 35516602951.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14025191184 + 1895470369 = 118428^2 + 43537^2 .

It is a cyclic number.

It is not a de Polignac number, because 15920661553 - 2⁵ = 15920661521 is a prime.

It is not a weakly prime, because it can be changed into another prime (15920661557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7960330776 + 7960330777.

It is an arithmetic number, because the mean of its divisors is an integer number (7960330777).

Almost surely, 2^15920661553 is an apocalyptic number.

It is an amenable number.

15920661553 is a deficient number, since it is larger than the sum of its proper divisors (1).

15920661553 is an equidigital number, since it uses as much as digits as its factorization.

15920661553 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 243000, while the sum is 43.

The spelling of 15920661553 in words is "fifteen billion, nine hundred twenty million, six hundred sixty-one thousand, five hundred fifty-three".