123440157 has 12 divisors (see below), whose sum is σ = 178536540. Its totient is φ = 82185408.

The previous prime is 123440137. The next prime is 123440167. The reversal of 123440157 is 751044321.

It can be written as a sum of positive squares in 2 ways, for example, as 57927321 + 65512836 = 7611^2 + 8094^2 .

It is not a de Polignac number, because 123440157 - 2¹⁹ = 122915869 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 123440157.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123440137) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1432 + ... + 15777.

It is an arithmetic number, because the mean of its divisors is an integer number (14878045).

Almost surely, 2^123440157 is an apocalyptic number.

It is an amenable number.

123440157 is a deficient number, since it is larger than the sum of its proper divisors (55096383).

123440157 is a wasteful number, since it uses less digits than its factorization.

123440157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18012 (or 18009 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 123440157 is about 11110.3625953431. The cubic root of 123440157 is about 497.9114977967.

Adding to 123440157 its reverse (751044321), we get a palindrome (874484478).

The spelling of 123440157 in words is "one hundred twenty-three million, four hundred forty thousand, one hundred fifty-seven".