1561164601 has 2 divisors, whose sum is σ = 1561164602. Its totient is φ = 1561164600.

The previous prime is 1561164571. The next prime is 1561164607. The reversal of 1561164601 is 1064611651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1060479225 + 500685376 = 32565^2 + 22376^2 .

It is an emirp because it is prime and its reverse (1064611651) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1561164601 is a prime.

It is a super-2 number, since 2×1561164601² = 4874469822830978402, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1561164607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780582300 + 780582301.

It is an arithmetic number, because the mean of its divisors is an integer number (780582301).

Almost surely, 2^1561164601 is an apocalyptic number.

It is an amenable number.

1561164601 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561164601 is an equidigital number, since it uses as much as digits as its factorization.

1561164601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 1561164601 is about 39511.5755317350. The cubic root of 1561164601 is about 1160.0665342832.

The spelling of 1561164601 in words is "one billion, five hundred sixty-one million, one hundred sixty-four thousand, six hundred one".