638642346 has 16 divisors (see below), whose sum is σ = 1318487808. Its totient is φ = 206013600.

The previous prime is 638642339. The next prime is 638642353. The reversal of 638642346 is 643246836.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (638642339) and next prime (638642353).

It is a super-2 number, since 2×638642346² = 815728092208767432, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 638642298 and 638642307.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1716595 + ... + 1716966.

It is an arithmetic number, because the mean of its divisors is an integer number (82405488).

Almost surely, 2^638642346 is an apocalyptic number.

638642346 is an abundant number, since it is smaller than the sum of its proper divisors (679845462).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638642346 is a wasteful number, since it uses less digits than its factorization.

638642346 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3433597.

The product of its digits is 497664, while the sum is 42.

The square root of 638642346 is about 25271.3740425803. The cubic root of 638642346 is about 861.1640744294.

The spelling of 638642346 in words is "six hundred thirty-eight million, six hundred forty-two thousand, three hundred forty-six".