709138921 has 8 divisors (see below), whose sum is σ = 751017024. Its totient is φ = 668181360.

The previous prime is 709138909. The next prime is 709138939. The reversal of 709138921 is 129831907.

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

It is a cyclic number.

It is not a de Polignac number, because 709138921 - 2⁵ = 709138889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (709138951) 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, 228550 + ... + 231631.

It is an arithmetic number, because the mean of its divisors is an integer number (93877128).

Almost surely, 2^709138921 is an apocalyptic number.

It is an amenable number.

709138921 is a deficient number, since it is larger than the sum of its proper divisors (41878103).

709138921 is a wasteful number, since it uses less digits than its factorization.

709138921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460271.

The product of its (nonzero) digits is 27216, while the sum is 40.

The square root of 709138921 is about 26629.6624274511. The cubic root of 709138921 is about 891.7513471193.

The spelling of 709138921 in words is "seven hundred nine million, one hundred thirty-eight thousand, nine hundred twenty-one".