156440401 has 4 divisors (see below), whose sum is σ = 168474292. Its totient is φ = 144406512.

The previous prime is 156440399. The next prime is 156440491. The reversal of 156440401 is 104044651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 104044651 = 257 ⋅404843.

It can be written as a sum of positive squares in 2 ways, for example, as 70896400 + 85544001 = 8420^2 + 9249^2 .

It is a cyclic number.

It is not a de Polignac number, because 156440401 - 2¹ = 156440399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (156440491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6016926 + ... + 6016951.

It is an arithmetic number, because the mean of its divisors is an integer number (42118573).

Almost surely, 2^156440401 is an apocalyptic number.

It is an amenable number.

156440401 is a deficient number, since it is larger than the sum of its proper divisors (12033891).

156440401 is a wasteful number, since it uses less digits than its factorization.

156440401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12033890.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 156440401 is about 12507.6137212499. The cubic root of 156440401 is about 538.8273605137.

The spelling of 156440401 in words is "one hundred fifty-six million, four hundred forty thousand, four hundred one".