971642638 has 4 divisors (see below), whose sum is σ = 1457463960. Its totient is φ = 485821318.

The previous prime is 971642561. The next prime is 971642657. The reversal of 971642638 is 836246179.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 836246179 = 14983 ⋅55813.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 242910658 + ... + 242910661.

It is an arithmetic number, because the mean of its divisors is an integer number (364365990).

Almost surely, 2^971642638 is an apocalyptic number.

971642638 is a deficient number, since it is larger than the sum of its proper divisors (485821322).

971642638 is a wasteful number, since it uses less digits than its factorization.

971642638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 485821321.

The product of its digits is 435456, while the sum is 46.

The square root of 971642638 is about 31171.1828136181. The cubic root of 971642638 is about 990.4567623264.

The spelling of 971642638 in words is "nine hundred seventy-one million, six hundred forty-two thousand, six hundred thirty-eight".