991060421 has 16 divisors (see below), whose sum is σ = 1115036160. Its totient is φ = 874618560.

The previous prime is 991060417. The next prime is 991060439. The reversal of 991060421 is 124060199.

It is a cyclic number.

It is not a de Polignac number, because 991060421 - 2² = 991060417 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991062421) 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, 18635 + ... + 48263.

It is an arithmetic number, because the mean of its divisors is an integer number (69689760).

Almost surely, 2^991060421 is an apocalyptic number.

It is an amenable number.

991060421 is a deficient number, since it is larger than the sum of its proper divisors (123975739).

991060421 is a wasteful number, since it uses less digits than its factorization.

991060421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29756.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 991060421 is about 31481.1121309270. The cubic root of 991060421 is about 997.0112164054.

The spelling of 991060421 in words is "nine hundred ninety-one million, sixty thousand, four hundred twenty-one".