121287137 has 4 divisors (see below), whose sum is σ = 121328580. Its totient is φ = 121245696.

The previous prime is 121287121. The next prime is 121287157. The reversal of 121287137 is 731782121.

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 104673361 + 16613776 = 10231^2 + 4076^2 .

It is a cyclic number.

It is not a de Polignac number, because 121287137 - 2⁴ = 121287121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121287157) 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, 15968 + ... + 22305.

It is an arithmetic number, because the mean of its divisors is an integer number (30332145).

Almost surely, 2^121287137 is an apocalyptic number.

It is an amenable number.

121287137 is a deficient number, since it is larger than the sum of its proper divisors (41443).

121287137 is an equidigital number, since it uses as much as digits as its factorization.

121287137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41442.

The product of its digits is 4704, while the sum is 32.

The square root of 121287137 is about 11013.0439479737. The cubic root of 121287137 is about 494.9996762233. Note that the first 3 decimals are identical.

The spelling of 121287137 in words is "one hundred twenty-one million, two hundred eighty-seven thousand, one hundred thirty-seven".