1001661631 has 2 divisors, whose sum is σ = 1001661632. Its totient is φ = 1001661630.

The previous prime is 1001661593. The next prime is 1001661637. The reversal of 1001661631 is 1361661001.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1001661631 - 2⁷ = 1001661503 is a prime.

It is a super-2 number, since 2×1001661631² = 2006652046035160322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1001661596 and 1001661605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1001661637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500830815 + 500830816.

It is an arithmetic number, because the mean of its divisors is an integer number (500830816).

Almost surely, 2^1001661631 is an apocalyptic number.

1001661631 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001661631 is an equidigital number, since it uses as much as digits as its factorization.

1001661631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 1001661631 is about 31649.0383898153. The cubic root of 1001661631 is about 1000.5535705032.

The spelling of 1001661631 in words is "one billion, one million, six hundred sixty-one thousand, six hundred thirty-one".