685720922 has 4 divisors (see below), whose sum is σ = 1028581386. Its totient is φ = 342860460.

The previous prime is 685720909. The next prime is 685720933. The reversal of 685720922 is 229027586.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 229027586 = 2 ⋅114513793.

It can be written as a sum of positive squares in only one way, i.e., 610534681 + 75186241 = 24709^2 + 8671^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 685720922.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171430229 + ... + 171430232.

Almost surely, 2^685720922 is an apocalyptic number.

685720922 is a deficient number, since it is larger than the sum of its proper divisors (342860464).

685720922 is a wasteful number, since it uses less digits than its factorization.

685720922 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342860463.

The product of its (nonzero) digits is 120960, while the sum is 41.

The square root of 685720922 is about 26186.2735416859. The cubic root of 685720922 is about 881.8251213417.

The spelling of 685720922 in words is "six hundred eighty-five million, seven hundred twenty thousand, nine hundred twenty-two".