991522 has 8 divisors (see below), whose sum is σ = 1699776. Its totient is φ = 424932.

The previous prime is 991511. The next prime is 991531. The reversal of 991522 is 225199.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35398 + ... + 35425.

It is an arithmetic number, because the mean of its divisors is an integer number (212472).

2⁹⁹¹⁵²² is an apocalyptic number.

991522 is a deficient number, since it is larger than the sum of its proper divisors (708254).

991522 is a wasteful number, since it uses less digits than its factorization.

991522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70832.

The product of its digits is 1620, while the sum is 28.

The square root of 991522 is about 995.7519771509. The cubic root of 991522 is about 99.7165975895.

It can be divided in two parts, 9915 and 22, that multiplied together give a triangular number (218130 = T₆₆₀).

The spelling of 991522 in words is "nine hundred ninety-one thousand, five hundred twenty-two".