122391561 has 4 divisors (see below), whose sum is σ = 163188752. Its totient is φ = 81594372.

The previous prime is 122391541. The next prime is 122391583. The reversal of 122391561 is 165193221.

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: 165193221 = 3 ⋅55064407.

It is not a de Polignac number, because 122391561 - 2¹¹ = 122389513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (122391541) 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, 20398591 + ... + 20398596.

It is an arithmetic number, because the mean of its divisors is an integer number (40797188).

Almost surely, 2^122391561 is an apocalyptic number.

It is an amenable number.

122391561 is a deficient number, since it is larger than the sum of its proper divisors (40797191).

122391561 is an equidigital number, since it uses as much as digits as its factorization.

122391561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40797190.

The product of its digits is 3240, while the sum is 30.

The square root of 122391561 is about 11063.0719513162. The cubic root of 122391561 is about 496.4976050770.

The spelling of 122391561 in words is "one hundred twenty-two million, three hundred ninety-one thousand, five hundred sixty-one".