691297152 has 256 divisors, whose sum is σ = 2299422720. Its totient is φ = 179159040.

The previous prime is 691297151. The next prime is 691297153. The reversal of 691297152 is 251792196.

It is an interprime number because it is at equal distance from previous prime (691297151) and next prime (691297153).

It is a super-2 number, since 2×691297152² = 955783504726622208, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691297151) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2550777 + ... + 2551047.

It is an arithmetic number, because the mean of its divisors is an integer number (8982120).

Almost surely, 2^691297152 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 691297152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1149711360).

691297152 is an abundant number, since it is smaller than the sum of its proper divisors (1608125568).

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

691297152 is a wasteful number, since it uses less digits than its factorization.

691297152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381 (or 369 counting only the distinct ones).

The product of its digits is 68040, while the sum is 42.

The square root of 691297152 is about 26292.5303460888. The cubic root of 691297152 is about 884.2089826205.

The spelling of 691297152 in words is "six hundred ninety-one million, two hundred ninety-seven thousand, one hundred fifty-two".