691579540 has 24 divisors (see below), whose sum is σ = 1457850240. Its totient is φ = 275577888.

The previous prime is 691579531. The next prime is 691579541. The reversal of 691579540 is 45975196.

It is a super-2 number, since 2×691579540² = 956564520293223200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691579541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60480 + ... + 70999.

It is an arithmetic number, because the mean of its divisors is an integer number (60743760).

Almost surely, 2^691579540 is an apocalyptic number.

It is an amenable number.

691579540 is an abundant number, since it is smaller than the sum of its proper divisors (766270700).

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

691579540 is a wasteful number, since it uses less digits than its factorization.

691579540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131751 (or 131749 counting only the distinct ones).

The product of its (nonzero) digits is 340200, while the sum is 46.

The square root of 691579540 is about 26297.8999161530. The cubic root of 691579540 is about 884.3293630843.

The spelling of 691579540 in words is "six hundred ninety-one million, five hundred seventy-nine thousand, five hundred forty".