122978155 has 4 divisors (see below), whose sum is σ = 147573792. Its totient is φ = 98382520.

The previous prime is 122978143. The next prime is 122978159. The reversal of 122978155 is 551879221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 551879221 = 3557 ⋅155153.

It is not a de Polignac number, because 122978155 - 2⁵ = 122978123 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (122978159) 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, 12297811 + ... + 12297820.

It is an arithmetic number, because the mean of its divisors is an integer number (36893448).

Almost surely, 2^122978155 is an apocalyptic number.

122978155 is a deficient number, since it is larger than the sum of its proper divisors (24595637).

122978155 is an equidigital number, since it uses as much as digits as its factorization.

122978155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24595636.

The product of its digits is 50400, while the sum is 40.

The square root of 122978155 is about 11089.5516140194. The cubic root of 122978155 is about 497.2895400304.

The spelling of 122978155 in words is "one hundred twenty-two million, nine hundred seventy-eight thousand, one hundred fifty-five".