1491489631 has 2 divisors, whose sum is σ = 1491489632. Its totient is φ = 1491489630.

The previous prime is 1491489583. The next prime is 1491489661. The reversal of 1491489631 is 1369841941.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1491489631 - 2²¹ = 1489392479 is a prime.

It is a super-2 number, since 2×1491489631² = 4449082638761032322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1491489661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 745744815 + 745744816.

It is an arithmetic number, because the mean of its divisors is an integer number (745744816).

Almost surely, 2^1491489631 is an apocalyptic number.

1491489631 is a deficient number, since it is larger than the sum of its proper divisors (1).

1491489631 is an equidigital number, since it uses as much as digits as its factorization.

1491489631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 186624, while the sum is 46.

The square root of 1491489631 is about 38619.8087903086. The cubic root of 1491489631 is about 1142.5452597118.

The spelling of 1491489631 in words is "one billion, four hundred ninety-one million, four hundred eighty-nine thousand, six hundred thirty-one".