691406772 has 96 divisors (see below), whose sum is σ = 1941553152. Its totient is φ = 187224576.

The previous prime is 691406759. The next prime is 691406773. The reversal of 691406772 is 277604196.

691406772 is nontrivially palindromic in base 5.

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 (691406773) 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, 216733 + ... + 219899.

It is an arithmetic number, because the mean of its divisors is an integer number (20224512).

Almost surely, 2^691406772 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 691406772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (970776576).

691406772 is an abundant number, since it is smaller than the sum of its proper divisors (1250146380).

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

691406772 is a wasteful number, since it uses less digits than its factorization.

691406772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3317 (or 3315 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 42.

The square root of 691406772 is about 26294.6148859420. The cubic root of 691406772 is about 884.2557169207.

The spelling of 691406772 in words is "six hundred ninety-one million, four hundred six thousand, seven hundred seventy-two".