121856365 has 4 divisors (see below), whose sum is σ = 146227644. Its totient is φ = 97485088.

The previous prime is 121856363. The next prime is 121856401. The reversal of 121856365 is 563658121.

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

It can be written as a sum of positive squares in 2 ways, for example, as 61685316 + 60171049 = 7854^2 + 7757^2 .

It is a cyclic number.

It is not a de Polignac number, because 121856365 - 2¹ = 121856363 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121856363) 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, 12185632 + ... + 12185641.

It is an arithmetic number, because the mean of its divisors is an integer number (36556911).

Almost surely, 2^121856365 is an apocalyptic number.

It is an amenable number.

121856365 is a deficient number, since it is larger than the sum of its proper divisors (24371279).

121856365 is an equidigital number, since it uses as much as digits as its factorization.

121856365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24371278.

The product of its digits is 43200, while the sum is 37.

The square root of 121856365 is about 11038.8570513437. The cubic root of 121856365 is about 495.7728497808.

It can be divided in two parts, 121856 and 365, that added together give a palindrome (122221).

The spelling of 121856365 in words is "one hundred twenty-one million, eight hundred fifty-six thousand, three hundred sixty-five".