721377138 has 8 divisors (see below), whose sum is σ = 1442754288. Its totient is φ = 240459044.

The previous prime is 721377127. The next prime is 721377143. The reversal of 721377138 is 831773127.

It is a sphenic number, since it is the product of 3 distinct primes.

721377138 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 721377096 and 721377105.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 60114756 + ... + 60114767.

It is an arithmetic number, because the mean of its divisors is an integer number (180344286).

Almost surely, 2^721377138 is an apocalyptic number.

721377138 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

721377138 is a wasteful number, since it uses less digits than its factorization.

721377138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120229528.

The product of its digits is 49392, while the sum is 39.

The square root of 721377138 is about 26858.4649226273. The cubic root of 721377138 is about 896.8520217385.

The spelling of 721377138 in words is "seven hundred twenty-one million, three hundred seventy-seven thousand, one hundred thirty-eight".