691204291440 has 160 divisors (see below), whose sum is σ = 2320309782336. Its totient is φ = 169202442240.

The previous prime is 691204291423. The next prime is 691204291471. The reversal of 691204291440 is 44192402196.

It is a junction number, because it is equal to n+sod(n) for n = 691204291392 and 691204291401.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 47269 + ... + 1176708.

Almost surely, 2^691204291440 is an apocalyptic number.

691204291440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 691204291440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1160154891168).

691204291440 is an abundant number, since it is smaller than the sum of its proper divisors (1629105490896).

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

691204291440 is a wasteful number, since it uses less digits than its factorization.

691204291440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1224187 (or 1224181 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 42.

The spelling of 691204291440 in words is "six hundred ninety-one billion, two hundred four million, two hundred ninety-one thousand, four hundred forty".