121010991 has 8 divisors (see below), whose sum is σ = 161444784. Its totient is φ = 80625600.

The previous prime is 121010983. The next prime is 121010999. The reversal of 121010991 is 199010121.

It is an interprime number because it is at equal distance from previous prime (121010983) and next prime (121010999).

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

It is not a de Polignac number, because 121010991 - 2³ = 121010983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121010999) 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, 5796 + ... + 16601.

It is an arithmetic number, because the mean of its divisors is an integer number (20180598).

Almost surely, 2^121010991 is an apocalyptic number.

121010991 is a deficient number, since it is larger than the sum of its proper divisors (40433793).

121010991 is a wasteful number, since it uses less digits than its factorization.

121010991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24201.

The product of its (nonzero) digits is 162, while the sum is 24.

The square root of 121010991 is about 11000.4995795646. The cubic root of 121010991 is about 494.6237197522.

The spelling of 121010991 in words is "one hundred twenty-one million, ten thousand, nine hundred ninety-one".