339996721 has 3 divisors (see below), whose sum is σ = 340015161. Its totient is φ = 339978282.

The previous prime is 339996703. The next prime is 339996733. The reversal of 339996721 is 127699933.

The square root of 339996721 is 18439.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 127699933 = 23 ⋅5552171.

It is not a de Polignac number, because 339996721 - 2⁵ = 339996689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (339996751) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 9220 + ... + 27658.

It is an arithmetic number, because the mean of its divisors is an integer number (113338387).

Almost surely, 2^339996721 is an apocalyptic number.

339996721 is the 18439-th square number.

339996721 is the 9220-th centered octagonal number.

It is an amenable number.

339996721 is a deficient number, since it is larger than the sum of its proper divisors (18440).

339996721 is an frugal number, since it uses more digits than its factorization.

339996721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36878 (or 18439 counting only the distinct ones).

The product of its digits is 551124, while the sum is 49.

The cubic root of 339996721 is about 697.9509609694.

Multiplying 339996721 by its sum of digits (49), we get a square (16659839329 = 129073²).

The spelling of 339996721 in words is "three hundred thirty-nine million, nine hundred ninety-six thousand, seven hundred twenty-one".