156223621 has 4 divisors (see below), whose sum is σ = 156723052. Its totient is φ = 155724192.

The previous prime is 156223619. The next prime is 156223631. The reversal of 156223621 is 126322651.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1718721 + 154504900 = 1311^2 + 12430^2 .

It is a cyclic number.

It is not a de Polignac number, because 156223621 - 2¹ = 156223619 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 156223621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (156223631) 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, 249246 + ... + 249871.

It is an arithmetic number, because the mean of its divisors is an integer number (39180763).

Almost surely, 2^156223621 is an apocalyptic number.

It is an amenable number.

156223621 is a deficient number, since it is larger than the sum of its proper divisors (499431).

156223621 is an equidigital number, since it uses as much as digits as its factorization.

156223621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 499430.

The product of its digits is 4320, while the sum is 28.

The square root of 156223621 is about 12498.9447954617. The cubic root of 156223621 is about 538.5783604913.

The spelling of 156223621 in words is "one hundred fifty-six million, two hundred twenty-three thousand, six hundred twenty-one".