1561897651933 has 2 divisors, whose sum is σ = 1561897651934. Its totient is φ = 1561897651932.

The previous prime is 1561897651889. The next prime is 1561897651991. The reversal of 1561897651933 is 3391567981651.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1561555142884 + 342509049 = 1249622^2 + 18507^2 .

It is a cyclic number.

It is not a de Polignac number, because 1561897651933 - 2²⁹ = 1561360781021 is a prime.

It is a super-2 number, since 2×1561897651933² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1561897651033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780948825966 + 780948825967.

It is an arithmetic number, because the mean of its divisors is an integer number (780948825967).

Almost surely, 2^{1561897651933} is an apocalyptic number.

It is an amenable number.

1561897651933 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561897651933 is an equidigital number, since it uses as much as digits as its factorization.

1561897651933 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36741600, while the sum is 64.

The spelling of 1561897651933 in words is "one trillion, five hundred sixty-one billion, eight hundred ninety-seven million, six hundred fifty-one thousand, nine hundred thirty-three".