1691397864 has 96 divisors (see below), whose sum is σ = 5223483720. Its totient is φ = 489811968.

The previous prime is 1691397863. The next prime is 1691397871. The reversal of 1691397864 is 4687931961.

It can be written as a sum of positive squares in 4 ways, for example, as 1467656100 + 223741764 = 38310^2 + 14958^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1691397864.

It is not an unprimeable number, because it can be changed into a prime (1691397863) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 37237 + ... + 69060.

Almost surely, 2^1691397864 is an apocalyptic number.

It is an amenable number.

1691397864 is an abundant number, since it is smaller than the sum of its proper divisors (3532085856).

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

1691397864 is a wasteful number, since it uses less digits than its factorization.

1691397864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106339 (or 106332 counting only the distinct ones).

The product of its digits is 1959552, while the sum is 54.

The square root of 1691397864 is about 41126.6077375706. The cubic root of 1691397864 is about 1191.4667468254.

The spelling of 1691397864 in words is "one billion, six hundred ninety-one million, three hundred ninety-seven thousand, eight hundred sixty-four".