291985640690 has 16 divisors (see below), whose sum is σ = 526494608640. Its totient is φ = 116589710640.

The previous prime is 291985640689. The next prime is 291985640729. The reversal of 291985640690 is 96046589192.

It is a super-2 number, since 2×291985640690² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25562210 + ... + 25573629.

It is an arithmetic number, because the mean of its divisors is an integer number (32905913040).

Almost surely, 2^291985640690 is an apocalyptic number.

291985640690 is a deficient number, since it is larger than the sum of its proper divisors (234508967950).

291985640690 is a wasteful number, since it uses less digits than its factorization.

291985640690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51136417.

The product of its (nonzero) digits is 8398080, while the sum is 59.

The spelling of 291985640690 in words is "two hundred ninety-one billion, nine hundred eighty-five million, six hundred forty thousand, six hundred ninety".