721336747 has 4 divisors (see below), whose sum is σ = 726526360. Its totient is φ = 716147136.

The previous prime is 721336727. The next prime is 721336751. The reversal of 721336747 is 747633127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 747633127 = 1327 ⋅563401.

It is a cyclic number.

It is not a de Polignac number, because 721336747 - 2⁷ = 721336619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (721336727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2594598 + ... + 2594875.

It is an arithmetic number, because the mean of its divisors is an integer number (181631590).

Almost surely, 2^721336747 is an apocalyptic number.

721336747 is a deficient number, since it is larger than the sum of its proper divisors (5189613).

721336747 is a wasteful number, since it uses less digits than its factorization.

721336747 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5189612.

The product of its digits is 148176, while the sum is 40.

The square root of 721336747 is about 26857.7129890093. The cubic root of 721336747 is about 896.8352827244.

The spelling of 721336747 in words is "seven hundred twenty-one million, three hundred thirty-six thousand, seven hundred forty-seven".