121287865 has 16 divisors (see below), whose sum is σ = 148055040. Its totient is φ = 95370880.

The previous prime is 121287863. The next prime is 121287923. The reversal of 121287865 is 568782121.

It is not a de Polignac number, because 121287865 - 2¹ = 121287863 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121287863) 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, 84282 + ... + 85708.

It is an arithmetic number, because the mean of its divisors is an integer number (9253440).

Almost surely, 2^121287865 is an apocalyptic number.

It is an amenable number.

121287865 is a deficient number, since it is larger than the sum of its proper divisors (26767175).

121287865 is a wasteful number, since it uses less digits than its factorization.

121287865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1712.

The product of its digits is 53760, while the sum is 40.

The square root of 121287865 is about 11013.0769996400. The cubic root of 121287865 is about 495.0006665977. Note that the first 3 decimals are identical.

The spelling of 121287865 in words is "one hundred twenty-one million, two hundred eighty-seven thousand, eight hundred sixty-five".