156552213221 has 2 divisors, whose sum is σ = 156552213222. Its totient is φ = 156552213220.

The previous prime is 156552213203. The next prime is 156552213227. The reversal of 156552213221 is 122312255651.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91342972900 + 65209240321 = 302230^2 + 255361^2 .

It is a cyclic number.

It is not a de Polignac number, because 156552213221 - 2⁶ = 156552213157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (156552213227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78276106610 + 78276106611.

It is an arithmetic number, because the mean of its divisors is an integer number (78276106611).

Almost surely, 2^156552213221 is an apocalyptic number.

It is an amenable number.

156552213221 is a deficient number, since it is larger than the sum of its proper divisors (1).

156552213221 is an equidigital number, since it uses as much as digits as its factorization.

156552213221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36000, while the sum is 35.

Adding to 156552213221 its reverse (122312255651), we get a palindrome (278864468872).

The spelling of 156552213221 in words is "one hundred fifty-six billion, five hundred fifty-two million, two hundred thirteen thousand, two hundred twenty-one".