1640311973 has 2 divisors, whose sum is σ = 1640311974. Its totient is φ = 1640311972.

The previous prime is 1640311951. The next prime is 1640312027. The reversal of 1640311973 is 3791130461.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1549052164 + 91259809 = 39358^2 + 9553^2 .

It is a cyclic number.

It is not a de Polignac number, because 1640311973 - 2¹⁶ = 1640246437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1640311273) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820155986 + 820155987.

It is an arithmetic number, because the mean of its divisors is an integer number (820155987).

Almost surely, 2^1640311973 is an apocalyptic number.

It is an amenable number.

1640311973 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640311973 is an equidigital number, since it uses as much as digits as its factorization.

1640311973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 1640311973 is about 40500.7650915387. The cubic root of 1640311973 is about 1179.3484799922.

The spelling of 1640311973 in words is "one billion, six hundred forty million, three hundred eleven thousand, nine hundred seventy-three".