121256805 has 16 divisors (see below), whose sum is σ = 202446720. Its totient is φ = 61858368.

The previous prime is 121256791. The next prime is 121256809. The reversal of 121256805 is 508652121.

It is not a de Polignac number, because 121256805 - 2⁸ = 121256549 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121256809) 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, 175390 + ... + 176079.

It is an arithmetic number, because the mean of its divisors is an integer number (12652920).

Almost surely, 2^121256805 is an apocalyptic number.

121256805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121256805 is a deficient number, since it is larger than the sum of its proper divisors (81189915).

121256805 is a wasteful number, since it uses less digits than its factorization.

121256805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351500.

The product of its (nonzero) digits is 4800, while the sum is 30.

The square root of 121256805 is about 11011.6667675697. Note that the first 3 decimals coincide. The cubic root of 121256805 is about 494.9584089124.

The spelling of 121256805 in words is "one hundred twenty-one million, two hundred fifty-six thousand, eight hundred five".