91290981 has 8 divisors (see below), whose sum is σ = 121797760. Its totient is φ = 60822432.

The previous prime is 91290977. The next prime is 91291007. The reversal of 91290981 is 18909219.

It is a happy number.

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

It is not a de Polignac number, because 91290981 - 2² = 91290977 is a prime.

It is a super-2 number, since 2×91290981² = 16668086423884722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91290931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3421 + ... + 13938.

It is an arithmetic number, because the mean of its divisors is an integer number (15224720).

Almost surely, 2^91290981 is an apocalyptic number.

It is an amenable number.

91290981 is a deficient number, since it is larger than the sum of its proper divisors (30506779).

91290981 is a wasteful number, since it uses less digits than its factorization.

91290981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19115.

The product of its (nonzero) digits is 11664, while the sum is 39.

The square root of 91290981 is about 9554.6313900642. The cubic root of 91290981 is about 450.2730540340.

The spelling of 91290981 in words is "ninety-one million, two hundred ninety thousand, nine hundred eighty-one".