156456221 has 4 divisors (see below), whose sum is σ = 156481344. Its totient is φ = 156431100.

The previous prime is 156456217. The next prime is 156456227. The reversal of 156456221 is 122654651.

156456221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 122654651 = 7 ⋅17522093.

It is a cyclic number.

It is not a de Polignac number, because 156456221 - 2² = 156456217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (156456227) 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, 4556 + ... + 18266.

It is an arithmetic number, because the mean of its divisors is an integer number (39120336).

Almost surely, 2^156456221 is an apocalyptic number.

It is an amenable number.

156456221 is a deficient number, since it is larger than the sum of its proper divisors (25123).

156456221 is a wasteful number, since it uses less digits than its factorization.

156456221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25122.

The product of its digits is 14400, while the sum is 32.

The square root of 156456221 is about 12508.2461200602. The cubic root of 156456221 is about 538.8455228330.

The spelling of 156456221 in words is "one hundred fifty-six million, four hundred fifty-six thousand, two hundred twenty-one".