121856506 has 4 divisors (see below), whose sum is σ = 182784762. Its totient is φ = 60928252.

The previous prime is 121856411. The next prime is 121856531. The reversal of 121856506 is 605658121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 605658121 = 47 ⋅12886343.

It can be written as a sum of positive squares in only one way, i.e., 98188281 + 23668225 = 9909^2 + 4865^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30464125 + ... + 30464128.

Almost surely, 2^121856506 is an apocalyptic number.

121856506 is a deficient number, since it is larger than the sum of its proper divisors (60928256).

121856506 is an equidigital number, since it uses as much as digits as its factorization.

121856506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60928255.

The product of its (nonzero) digits is 14400, while the sum is 34.

The square root of 121856506 is about 11038.8634378726. The cubic root of 121856506 is about 495.7730410004.

The spelling of 121856506 in words is "one hundred twenty-one million, eight hundred fifty-six thousand, five hundred six".