1011561631 has 2 divisors, whose sum is σ = 1011561632. Its totient is φ = 1011561630.

The previous prime is 1011561601. The next prime is 1011561701. The reversal of 1011561631 is 1361651101.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1011561631 - 2¹¹ = 1011559583 is a prime.

It is a super-2 number, since 2×1011561631² = 2046513866622760322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1011561596 and 1011561605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1011561601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 505780815 + 505780816.

It is an arithmetic number, because the mean of its divisors is an integer number (505780816).

Almost surely, 2^1011561631 is an apocalyptic number.

1011561631 is a deficient number, since it is larger than the sum of its proper divisors (1).

1011561631 is an equidigital number, since it uses as much as digits as its factorization.

1011561631 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 540, while the sum is 25.

The square root of 1011561631 is about 31805.0566891493. The cubic root of 1011561631 is about 1003.8391193016.

The spelling of 1011561631 in words is "one billion, eleven million, five hundred sixty-one thousand, six hundred thirty-one".