121256731 has 4 divisors (see below), whose sum is σ = 121337464. Its totient is φ = 121176000.

The previous prime is 121256719. The next prime is 121256747. The reversal of 121256731 is 137652121.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121256731 is a prime.

It is a super-2 number, since 2×121256731² = 29406389625612722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121256731.

It is not an unprimeable number, because it can be changed into a prime (121256761) 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, 38070 + ... + 41131.

It is an arithmetic number, because the mean of its divisors is an integer number (30334366).

Almost surely, 2^121256731 is an apocalyptic number.

121256731 is a deficient number, since it is larger than the sum of its proper divisors (80733).

121256731 is an equidigital number, since it uses as much as digits as its factorization.

121256731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80732.

The product of its digits is 2520, while the sum is 28.

The square root of 121256731 is about 11011.6634074966. The cubic root of 121256731 is about 494.9583082255.

The spelling of 121256731 in words is "one hundred twenty-one million, two hundred fifty-six thousand, seven hundred thirty-one".