1656615651 has 16 divisors (see below), whose sum is σ = 2250737280. Its totient is φ = 1083642560.

The previous prime is 1656615637. The next prime is 1656615659. The reversal of 1656615651 is 1565166561.

It is a cyclic number.

It is not a de Polignac number, because 1656615651 - 2¹⁴ = 1656599267 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1656615659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11296 + ... + 58658.

It is an arithmetic number, because the mean of its divisors is an integer number (140671080).

Almost surely, 2^1656615651 is an apocalyptic number.

1656615651 is a deficient number, since it is larger than the sum of its proper divisors (594121629).

1656615651 is a wasteful number, since it uses less digits than its factorization.

1656615651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47586.

The product of its digits is 162000, while the sum is 42.

The square root of 1656615651 is about 40701.5435948073. The cubic root of 1656615651 is about 1183.2429349886.

The spelling of 1656615651 in words is "one billion, six hundred fifty-six million, six hundred fifteen thousand, six hundred fifty-one".