1640073731 has 2 divisors, whose sum is σ = 1640073732. Its totient is φ = 1640073730.

The previous prime is 1640073727. The next prime is 1640073763. The reversal of 1640073731 is 1373700461.

It is an a-pointer prime, because the next prime (1640073763) can be obtained adding 1640073731 to its sum of digits (32).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1640073731 - 2² = 1640073727 is a prime.

It is a super-2 number, since 2×1640073731² = 5379683686232520722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1640073931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820036865 + 820036866.

It is an arithmetic number, because the mean of its divisors is an integer number (820036866).

Almost surely, 2^1640073731 is an apocalyptic number.

1640073731 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640073731 is an equidigital number, since it uses as much as digits as its factorization.

1640073731 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10584, while the sum is 32.

The square root of 1640073731 is about 40497.8237810379. The cubic root of 1640073731 is about 1179.2913802963.

The spelling of 1640073731 in words is "one billion, six hundred forty million, seventy-three thousand, seven hundred thirty-one".