721690351 has 8 divisors (see below), whose sum is σ = 725321520. Its totient is φ = 718067712.

The previous prime is 721690339. The next prime is 721690367. The reversal of 721690351 is 153096127.

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 721690351 - 2¹⁹ = 721166063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721690051) 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, 223716 + ... + 226918.

It is an arithmetic number, because the mean of its divisors is an integer number (90665190).

Almost surely, 2^721690351 is an apocalyptic number.

721690351 is a deficient number, since it is larger than the sum of its proper divisors (3631169).

721690351 is a wasteful number, since it uses less digits than its factorization.

721690351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4265.

The product of its (nonzero) digits is 11340, while the sum is 34.

The square root of 721690351 is about 26864.2950959075. The cubic root of 721690351 is about 896.9818036293.

The spelling of 721690351 in words is "seven hundred twenty-one million, six hundred ninety thousand, three hundred fifty-one".