1656121253 has 4 divisors (see below), whose sum is σ = 1656209100. Its totient is φ = 1656033408.

The previous prime is 1656121223. The next prime is 1656121261. The reversal of 1656121253 is 3521216561.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 636149284 + 1019971969 = 25222^2 + 31937^2 .

It is a cyclic number.

It is not a de Polignac number, because 1656121253 - 2⁶ = 1656121189 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 (1656121223) 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 in 3 ways as a sum of consecutive naturals, for example, 2828 + ... + 57621.

It is an arithmetic number, because the mean of its divisors is an integer number (414052275).

Almost surely, 2^1656121253 is an apocalyptic number.

It is an amenable number.

1656121253 is a deficient number, since it is larger than the sum of its proper divisors (87847).

1656121253 is an equidigital number, since it uses as much as digits as its factorization.

1656121253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87846.

The product of its digits is 10800, while the sum is 32.

The square root of 1656121253 is about 40695.4696864405. The cubic root of 1656121253 is about 1183.1252148354.

The spelling of 1656121253 in words is "one billion, six hundred fifty-six million, one hundred twenty-one thousand, two hundred fifty-three".