1640155873 has 2 divisors, whose sum is σ = 1640155874. Its totient is φ = 1640155872.

The previous prime is 1640155859. The next prime is 1640155889. The reversal of 1640155873 is 3785510461.

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., 1355491489 + 284664384 = 36817^2 + 16872^2 .

It is a cyclic number.

It is not a de Polignac number, because 1640155873 - 2¹⁷ = 1640024801 is a prime.

It is a super-2 number, since 2×1640155873² = 5380222575472784258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1640155823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820077936 + 820077937.

It is an arithmetic number, because the mean of its divisors is an integer number (820077937).

Almost surely, 2^1640155873 is an apocalyptic number.

It is an amenable number.

1640155873 is a deficient number, since it is larger than the sum of its proper divisors (1).

1640155873 is an equidigital number, since it uses as much as digits as its factorization.

1640155873 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 100800, while the sum is 40.

The square root of 1640155873 is about 40498.8379215997. The cubic root of 1640155873 is about 1179.3110679753.

The spelling of 1640155873 in words is "one billion, six hundred forty million, one hundred fifty-five thousand, eight hundred seventy-three".