122857509 has 4 divisors (see below), whose sum is σ = 163810016. Its totient is φ = 81905004.

The previous prime is 122857499. The next prime is 122857517. The reversal of 122857509 is 905758221.

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: 905758221 = 3 ⋅301919407.

It is not a de Polignac number, because 122857509 - 2⁷ = 122857381 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (122857549) 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, 20476249 + ... + 20476254.

It is an arithmetic number, because the mean of its divisors is an integer number (40952504).

Almost surely, 2^122857509 is an apocalyptic number.

It is an amenable number.

122857509 is a deficient number, since it is larger than the sum of its proper divisors (40952507).

122857509 is an equidigital number, since it uses as much as digits as its factorization.

122857509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40952506.

The product of its (nonzero) digits is 50400, while the sum is 39.

The square root of 122857509 is about 11084.1106544458. The cubic root of 122857509 is about 497.1268671720.

The spelling of 122857509 in words is "one hundred twenty-two million, eight hundred fifty-seven thousand, five hundred nine".