121561365 has 16 divisors (see below), whose sum is σ = 194754816. Its totient is φ = 64747200.

The previous prime is 121561361. The next prime is 121561367. The reversal of 121561365 is 563165121.

It is not a de Polignac number, because 121561365 - 2² = 121561361 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121561361) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7380 + ... + 17250.

It is an arithmetic number, because the mean of its divisors is an integer number (12172176).

Almost surely, 2^121561365 is an apocalyptic number.

121561365 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121561365 is a deficient number, since it is larger than the sum of its proper divisors (73193451).

121561365 is an equidigital number, since it uses as much as digits as its factorization.

121561365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10700.

The product of its digits is 5400, while the sum is 30.

The square root of 121561365 is about 11025.4870640711. The cubic root of 121561365 is about 495.3724571543.

The spelling of 121561365 in words is "one hundred twenty-one million, five hundred sixty-one thousand, three hundred sixty-five".