646127638 has 16 divisors (see below), whose sum is σ = 1089125856. Its totient is φ = 285246720.

The previous prime is 646127621. The next prime is 646127639. The reversal of 646127638 is 836721646.

It is a junction number, because it is equal to n+sod(n) for n = 646127594 and 646127603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646127639) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 539643 + ... + 540838.

It is an arithmetic number, because the mean of its divisors is an integer number (68070366).

Almost surely, 2^646127638 is an apocalyptic number.

646127638 is a deficient number, since it is larger than the sum of its proper divisors (442998218).

646127638 is a wasteful number, since it uses less digits than its factorization.

646127638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1080519.

The product of its digits is 290304, while the sum is 43.

The square root of 646127638 is about 25419.0408552329. The cubic root of 646127638 is about 864.5154772542.

The spelling of 646127638 in words is "six hundred forty-six million, one hundred twenty-seven thousand, six hundred thirty-eight".