1662116721 has 16 divisors (see below), whose sum is σ = 2227268736. Its totient is φ = 1102536576.

The previous prime is 1662116719. The next prime is 1662116747. The reversal of 1662116721 is 1276112661.

It is not a de Polignac number, because 1662116721 - 2¹ = 1662116719 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1662116761) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 561381 + ... + 564333.

It is an arithmetic number, because the mean of its divisors is an integer number (139204296).

Almost surely, 2^1662116721 is an apocalyptic number.

It is an amenable number.

1662116721 is a deficient number, since it is larger than the sum of its proper divisors (565152015).

1662116721 is a wasteful number, since it uses less digits than its factorization.

1662116721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3832.

The product of its digits is 6048, while the sum is 33.

The square root of 1662116721 is about 40769.0657361682. The cubic root of 1662116721 is about 1184.5512067888.

The spelling of 1662116721 in words is "one billion, six hundred sixty-two million, one hundred sixteen thousand, seven hundred twenty-one".