12778157 has 4 divisors (see below), whose sum is σ = 14603616. Its totient is φ = 10952700.

The previous prime is 12778151. The next prime is 12778163. The reversal of 12778157 is 75187721.

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: 75187721 = 7 ⋅10741103.

It is an interprime number because it is at equal distance from previous prime (12778151) and next prime (12778163).

It is a cyclic number.

It is not a de Polignac number, because 12778157 - 2⁶ = 12778093 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12778157.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12778151) 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, 912719 + ... + 912732.

It is an arithmetic number, because the mean of its divisors is an integer number (3650904).

Almost surely, 2^12778157 is an apocalyptic number.

It is an amenable number.

12778157 is a deficient number, since it is larger than the sum of its proper divisors (1825459).

12778157 is an equidigital number, since it uses as much as digits as its factorization.

12778157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1825458.

The product of its digits is 27440, while the sum is 38.

The square root of 12778157 is about 3574.6548085095. The cubic root of 12778157 is about 233.7882822141.

The spelling of 12778157 in words is "twelve million, seven hundred seventy-eight thousand, one hundred fifty-seven".