720922691 has 4 divisors (see below), whose sum is σ = 723383472. Its totient is φ = 718461912.

The previous prime is 720922667. The next prime is 720922703. The reversal of 720922691 is 196229027.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 196229027 = 12541 ⋅15647.

It is a cyclic number.

It is not a de Polignac number, because 720922691 - 2¹⁰ = 720921667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (720922591) 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, 1229951 + ... + 1230536.

It is an arithmetic number, because the mean of its divisors is an integer number (180845868).

Almost surely, 2^720922691 is an apocalyptic number.

720922691 is a deficient number, since it is larger than the sum of its proper divisors (2460781).

720922691 is a wasteful number, since it uses less digits than its factorization.

720922691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2460780.

The product of its (nonzero) digits is 27216, while the sum is 38.

The square root of 720922691 is about 26850.0035567968. The cubic root of 720922691 is about 896.6636517882.

The spelling of 720922691 in words is "seven hundred twenty million, nine hundred twenty-two thousand, six hundred ninety-one".