1642631938 has 4 divisors (see below), whose sum is σ = 2463947910. Its totient is φ = 821315968.

The previous prime is 1642631929. The next prime is 1642631959. The reversal of 1642631938 is 8391362461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8391362461 = 39139 ⋅214399.

It can be written as a sum of positive squares in only one way, i.e., 1610176129 + 32455809 = 40127^2 + 5697^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1642631894 and 1642631903.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410657983 + ... + 410657986.

Almost surely, 2^1642631938 is an apocalyptic number.

1642631938 is a deficient number, since it is larger than the sum of its proper divisors (821315972).

1642631938 is an equidigital number, since it uses as much as digits as its factorization.

1642631938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 821315971.

The product of its digits is 186624, while the sum is 43.

The square root of 1642631938 is about 40529.3959737867. The cubic root of 1642631938 is about 1179.9042194593.

The spelling of 1642631938 in words is "one billion, six hundred forty-two million, six hundred thirty-one thousand, nine hundred thirty-eight".