1638074651 has 4 divisors (see below), whose sum is σ = 1709295312. Its totient is φ = 1566853992.

The previous prime is 1638074639. The next prime is 1638074653. The reversal of 1638074651 is 1564708361.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1564708361 = 173 ⋅9044557.

It is a cyclic number.

It is not a de Polignac number, because 1638074651 - 2⁶ = 1638074587 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1638074599 and 1638074608.

It is not an unprimeable number, because it can be changed into a prime (1638074653) 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 in 3 ways as a sum of consecutive naturals, for example, 35610296 + ... + 35610341.

It is an arithmetic number, because the mean of its divisors is an integer number (427323828).

Almost surely, 2^1638074651 is an apocalyptic number.

1638074651 is a deficient number, since it is larger than the sum of its proper divisors (71220661).

1638074651 is an equidigital number, since it uses as much as digits as its factorization.

1638074651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71220660.

The product of its (nonzero) digits is 120960, while the sum is 41.

The square root of 1638074651 is about 40473.1349292342. The cubic root of 1638074651 is about 1178.8120408077.

The spelling of 1638074651 in words is "one billion, six hundred thirty-eight million, seventy-four thousand, six hundred fifty-one".