691397370 has 40 divisors (see below), whose sum is σ = 1859092884. Its totient is φ = 184372416.

The previous prime is 691397339. The next prime is 691397417. The reversal of 691397370 is 73793196.

It can be written as a sum of positive squares in 2 ways, for example, as 661158369 + 30239001 = 25713^2 + 5499^2 .

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 425979 + ... + 427598.

Almost surely, 2^691397370 is an apocalyptic number.

691397370 is an abundant number, since it is smaller than the sum of its proper divisors (1167695514).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

691397370 is a wasteful number, since it uses less digits than its factorization.

691397370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 853596 (or 853587 counting only the distinct ones).

The product of its (nonzero) digits is 214326, while the sum is 45.

The square root of 691397370 is about 26294.4361034801. The cubic root of 691397370 is about 884.2517087592.

The spelling of 691397370 in words is "six hundred ninety-one million, three hundred ninety-seven thousand, three hundred seventy".