691249042 has 24 divisors (see below), whose sum is σ = 1155784896. Its totient is φ = 309771000.

The previous prime is 691249001. The next prime is 691249073. The reversal of 691249042 is 240942196.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 691248992 and 691249010.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2934 + ... + 37297.

It is an arithmetic number, because the mean of its divisors is an integer number (48157704).

Almost surely, 2^691249042 is an apocalyptic number.

691249042 is a deficient number, since it is larger than the sum of its proper divisors (464535854).

691249042 is a wasteful number, since it uses less digits than its factorization.

691249042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40326 (or 40315 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 691249042 is about 26291.6154315401. The cubic root of 691249042 is about 884.1884703218.

The spelling of 691249042 in words is "six hundred ninety-one million, two hundred forty-nine thousand, forty-two".