1656121223 has 2 divisors, whose sum is σ = 1656121224. Its totient is φ = 1656121222.

The previous prime is 1656121193. The next prime is 1656121261. The reversal of 1656121223 is 3221216561.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1656121223 - 2²² = 1651926919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1656121273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 828060611 + 828060612.

It is an arithmetic number, because the mean of its divisors is an integer number (828060612).

Almost surely, 2^1656121223 is an apocalyptic number.

1656121223 is a deficient number, since it is larger than the sum of its proper divisors (1).

1656121223 is an equidigital number, since it uses as much as digits as its factorization.

1656121223 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4320, while the sum is 29.

The square root of 1656121223 is about 40695.4693178491. The cubic root of 1656121223 is about 1183.1252076914.

Adding to 1656121223 its reverse (3221216561), we get a palindrome (4877337784).

The spelling of 1656121223 in words is "one billion, six hundred fifty-six million, one hundred twenty-one thousand, two hundred twenty-three".