721890678 has 16 divisors (see below), whose sum is σ = 1493567280. Its totient is φ = 232332576.

The previous prime is 721890671. The next prime is 721890691. The reversal of 721890678 is 876098127.

It is a super-2 number, since 2×721890678² = 1042252301966599368, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721890671) 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, 2074225 + ... + 2074572.

It is an arithmetic number, because the mean of its divisors is an integer number (93347955).

Almost surely, 2^721890678 is an apocalyptic number.

721890678 is an abundant number, since it is smaller than the sum of its proper divisors (771676602).

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

721890678 is a wasteful number, since it uses less digits than its factorization.

721890678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4148831.

The product of its (nonzero) digits is 338688, while the sum is 48.

The square root of 721890678 is about 26868.0233363007. The cubic root of 721890678 is about 897.0647907672.

The spelling of 721890678 in words is "seven hundred twenty-one million, eight hundred ninety thousand, six hundred seventy-eight".