491221023955 has 16 divisors (see below), whose sum is σ = 597040329600. Its totient is φ = 387928644480.

The previous prime is 491221023871. The next prime is 491221023959. The reversal of 491221023955 is 559320122194.

It is not a de Polignac number, because 491221023955 - 2⁷ = 491221023827 is a prime.

It is not an unprimeable number, because it can be changed into a prime (491221023959) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2009941 + ... + 2241049.

It is an arithmetic number, because the mean of its divisors is an integer number (37315020600).

Almost surely, 2^491221023955 is an apocalyptic number.

491221023955 is a deficient number, since it is larger than the sum of its proper divisors (105819305645).

491221023955 is a wasteful number, since it uses less digits than its factorization.

491221023955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236574.

The product of its (nonzero) digits is 194400, while the sum is 43.

The spelling of 491221023955 in words is "four hundred ninety-one billion, two hundred twenty-one million, twenty-three thousand, nine hundred fifty-five".