291040640 has 64 divisors (see below), whose sum is σ = 759039120. Its totient is φ = 105830400.

The previous prime is 291040639. The next prime is 291040669. The reversal of 291040640 is 46040192.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13631 + ... + 27710.

Almost surely, 2^291040640 is an apocalyptic number.

291040640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

291040640 is an abundant number, since it is smaller than the sum of its proper divisors (467998480).

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

291040640 is a wasteful number, since it uses less digits than its factorization.

291040640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41371 (or 41359 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 291040640 is about 17059.9132471417. The cubic root of 291040640 is about 662.7013860296.

The spelling of 291040640 in words is "two hundred ninety-one million, forty thousand, six hundred forty".