121264561 has 4 divisors (see below), whose sum is σ = 132288624. Its totient is φ = 110240500.

The previous prime is 121264513. The next prime is 121264657. The reversal of 121264561 is 165462121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 165462121 = 11 ⋅15042011.

It is a cyclic number.

It is not a de Polignac number, because 121264561 - 2⁷ = 121264433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121264861) 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, 5512015 + ... + 5512036.

It is an arithmetic number, because the mean of its divisors is an integer number (33072156).

Almost surely, 2^121264561 is an apocalyptic number.

121264561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121264561 is a deficient number, since it is larger than the sum of its proper divisors (11024063).

121264561 is a wasteful number, since it uses less digits than its factorization.

121264561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11024062.

The product of its digits is 2880, while the sum is 28.

The square root of 121264561 is about 11012.0189338740. The cubic root of 121264561 is about 494.9689617650.

The spelling of 121264561 in words is "one hundred twenty-one million, two hundred sixty-four thousand, five hundred sixty-one".