10220991 has 24 divisors (see below), whose sum is σ = 15404592. Its totient is φ = 6019200.

The previous prime is 10220981. The next prime is 10221007. The reversal of 10220991 is 19902201.

It is not a de Polignac number, because 10220991 - 2⁷ = 10220863 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10220911) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13051 + ... + 13811.

It is an arithmetic number, because the mean of its divisors is an integer number (641858).

Almost surely, 2^10220991 is an apocalyptic number.

10220991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

10220991 is a deficient number, since it is larger than the sum of its proper divisors (5183601).

10220991 is a wasteful number, since it uses less digits than its factorization.

10220991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 823 (or 812 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 24.

The square root of 10220991 is about 3197.0284640585. The cubic root of 10220991 is about 217.0189553546.

It can be divided in two parts, 10220 and 991, that added together give a palindrome (11211).

The spelling of 10220991 in words is "ten million, two hundred twenty thousand, nine hundred ninety-one".