691054945 has 16 divisors (see below), whose sum is σ = 978306048. Its totient is φ = 458579520.

The previous prime is 691054907. The next prime is 691054961. The reversal of 691054945 is 549450196.

It is not a de Polignac number, because 691054945 - 2¹⁹ = 690530657 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 317374 + ... + 319543.

It is an arithmetic number, because the mean of its divisors is an integer number (61144128).

Almost surely, 2^691054945 is an apocalyptic number.

It is an amenable number.

691054945 is a deficient number, since it is larger than the sum of its proper divisors (287251103).

691054945 is a wasteful number, since it uses less digits than its factorization.

691054945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 636960.

The product of its (nonzero) digits is 194400, while the sum is 43.

The square root of 691054945 is about 26287.9239385692. The cubic root of 691054945 is about 884.1057049775.

The spelling of 691054945 in words is "six hundred ninety-one million, fifty-four thousand, nine hundred forty-five".