1656115221 has 16 divisors (see below), whose sum is σ = 2368232640. Its totient is φ = 1026230400.

The previous prime is 1656115217. The next prime is 1656115229. The reversal of 1656115221 is 1225116561.

It is not a de Polignac number, because 1656115221 - 2² = 1656115217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1656115229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 271080 + ... + 277121.

It is an arithmetic number, because the mean of its divisors is an integer number (148014540).

Almost surely, 2^1656115221 is an apocalyptic number.

It is an amenable number.

1656115221 is a deficient number, since it is larger than the sum of its proper divisors (712117419).

1656115221 is a wasteful number, since it uses less digits than its factorization.

1656115221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 548276.

The product of its digits is 3600, while the sum is 30.

The square root of 1656115221 is about 40695.3955749296. The cubic root of 1656115221 is about 1183.1237784228.

The spelling of 1656115221 in words is "one billion, six hundred fifty-six million, one hundred fifteen thousand, two hundred twenty-one".