1656141121 has 4 divisors (see below), whose sum is σ = 1658538544. Its totient is φ = 1653743700.

The previous prime is 1656141107. The next prime is 1656141143. The reversal of 1656141121 is 1211416561.

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 an emirpimes, since its reverse is a distinct semiprime: 1211416561 = 8293 ⋅146077.

It is a cyclic number.

It is not a de Polignac number, because 1656141121 - 2²⁵ = 1622586689 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 1656141121.

It is not an unprimeable number, because it can be changed into a prime (1656141161) 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, 1197675 + ... + 1199056.

It is an arithmetic number, because the mean of its divisors is an integer number (414634636).

Almost surely, 2^1656141121 is an apocalyptic number.

It is an amenable number.

1656141121 is a deficient number, since it is larger than the sum of its proper divisors (2397423).

1656141121 is an equidigital number, since it uses as much as digits as its factorization.

1656141121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2397422.

The product of its digits is 1440, while the sum is 28.

The square root of 1656141121 is about 40695.7137915039. The cubic root of 1656141121 is about 1183.1299460183.

Adding to 1656141121 its reverse (1211416561), we get a palindrome (2867557682).

The spelling of 1656141121 in words is "one billion, six hundred fifty-six million, one hundred forty-one thousand, one hundred twenty-one".