121690931 has 4 divisors (see below), whose sum is σ = 125887200. Its totient is φ = 117494664.

The previous prime is 121690909. The next prime is 121690937. The reversal of 121690931 is 139096121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 139096121 = 2081 ⋅66841.

It is a cyclic number.

It is not a de Polignac number, because 121690931 - 2⁶ = 121690867 is a prime.

It is a super-2 number, since 2×121690931² = 29617365375293522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121690937) 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, 2098091 + ... + 2098148.

It is an arithmetic number, because the mean of its divisors is an integer number (31471800).

Almost surely, 2^121690931 is an apocalyptic number.

121690931 is a deficient number, since it is larger than the sum of its proper divisors (4196269).

121690931 is an equidigital number, since it uses as much as digits as its factorization.

121690931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4196268.

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 121690931 is about 11031.3612487308. The cubic root of 121690931 is about 495.5483919946.

The spelling of 121690931 in words is "one hundred twenty-one million, six hundred ninety thousand, nine hundred thirty-one".