121920951 has 4 divisors (see below), whose sum is σ = 162561272. Its totient is φ = 81280632.

The previous prime is 121920947. The next prime is 121920971. The reversal of 121920951 is 159029121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 159029121 = 3 ⋅53009707.

It is not a de Polignac number, because 121920951 - 2² = 121920947 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121920971) 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, 20320156 + ... + 20320161.

It is an arithmetic number, because the mean of its divisors is an integer number (40640318).

Almost surely, 2^121920951 is an apocalyptic number.

121920951 is a deficient number, since it is larger than the sum of its proper divisors (40640321).

121920951 is an equidigital number, since it uses as much as digits as its factorization.

121920951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40640320.

The product of its (nonzero) digits is 1620, while the sum is 30.

The square root of 121920951 is about 11041.7820572587. The cubic root of 121920951 is about 495.8604237315.

The spelling of 121920951 in words is "one hundred twenty-one million, nine hundred twenty thousand, nine hundred fifty-one".