1653958666 has 4 divisors (see below), whose sum is σ = 2480938002. Its totient is φ = 826979332.

The previous prime is 1653958661. The next prime is 1653958687. The reversal of 1653958666 is 6668593561.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1044905625 + 609053041 = 32325^2 + 24679^2 .

It is not an unprimeable number, because it can be changed into a prime (1653958661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 413489665 + ... + 413489668.

Almost surely, 2^1653958666 is an apocalyptic number.

1653958666 is a deficient number, since it is larger than the sum of its proper divisors (826979336).

1653958666 is an equidigital number, since it uses as much as digits as its factorization.

1653958666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 826979335.

The product of its digits is 6998400, while the sum is 55.

The square root of 1653958666 is about 40668.8906413735. The cubic root of 1653958666 is about 1182.6100098640.

The spelling of 1653958666 in words is "one billion, six hundred fifty-three million, nine hundred fifty-eight thousand, six hundred sixty-six".