1638351553 has 2 divisors, whose sum is σ = 1638351554. Its totient is φ = 1638351552.

The previous prime is 1638351511. The next prime is 1638351563. The reversal of 1638351553 is 3551538361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1080305424 + 558046129 = 32868^2 + 23623^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1638351553 is a prime.

It is a super-2 number, since 2×1638351553² = 5368391622435023618, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1638351503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 819175776 + 819175777.

It is an arithmetic number, because the mean of its divisors is an integer number (819175777).

Almost surely, 2^1638351553 is an apocalyptic number.

It is an amenable number.

1638351553 is a deficient number, since it is larger than the sum of its proper divisors (1).

1638351553 is an equidigital number, since it uses as much as digits as its factorization.

1638351553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 162000, while the sum is 40.

The square root of 1638351553 is about 40476.5555970367. Note that the first 4 decimals coincide. The cubic root of 1638351553 is about 1178.8784596409.

The spelling of 1638351553 in words is "one billion, six hundred thirty-eight million, three hundred fifty-one thousand, five hundred fifty-three".