1561646627 has 2 divisors, whose sum is σ = 1561646628. Its totient is φ = 1561646626.

The previous prime is 1561646623. The next prime is 1561646683. The reversal of 1561646627 is 7266461651.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1561646627 - 2² = 1561646623 is a prime.

It is not a weakly prime, because it can be changed into another prime (1561646623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780823313 + 780823314.

It is an arithmetic number, because the mean of its divisors is an integer number (780823314).

Almost surely, 2^1561646627 is an apocalyptic number.

1561646627 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561646627 is an equidigital number, since it uses as much as digits as its factorization.

1561646627 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 44.

The square root of 1561646627 is about 39517.6748683421. The cubic root of 1561646627 is about 1160.1859162475.

The spelling of 1561646627 in words is "one billion, five hundred sixty-one million, six hundred forty-six thousand, six hundred twenty-seven".