991753 has 4 divisors (see below), whose sum is σ = 1133440. Its totient is φ = 850068.

The previous prime is 991751. The next prime is 991777. The reversal of 991753 is 357199.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 991753 - 2¹ = 991751 is a prime.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (991751) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70833 + ... + 70846.

It is an arithmetic number, because the mean of its divisors is an integer number (283360).

2⁹⁹¹⁷⁵³ is an apocalyptic number.

It is an amenable number.

991753 is a deficient number, since it is larger than the sum of its proper divisors (141687).

991753 is a wasteful number, since it uses less digits than its factorization.

991753 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141686.

The product of its digits is 8505, while the sum is 34.

The square root of 991753 is about 995.8679631357. The cubic root of 991753 is about 99.7243408184.

The spelling of 991753 in words is "nine hundred ninety-one thousand, seven hundred fifty-three".