634709978 has 16 divisors (see below), whose sum is σ = 1135382400. Its totient is φ = 260191536.

The previous prime is 634709969. The next prime is 634709987. The reversal of 634709978 is 879907436.

It is an interprime number because it is at equal distance from previous prime (634709969) and next prime (634709987).

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, 985253 + ... + 985896.

It is an arithmetic number, because the mean of its divisors is an integer number (70961400).

Almost surely, 2^634709978 is an apocalyptic number.

634709978 is a deficient number, since it is larger than the sum of its proper divisors (500672422).

634709978 is a wasteful number, since it uses less digits than its factorization.

634709978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1971181.

The product of its (nonzero) digits is 2286144, while the sum is 53.

The square root of 634709978 is about 25193.4510934886. The cubic root of 634709978 is about 859.3929274374.

The spelling of 634709978 in words is "six hundred thirty-four million, seven hundred nine thousand, nine hundred seventy-eight".