651616666 has 16 divisors (see below), whose sum is σ = 1033414560. Its totient is φ = 307296720.

The previous prime is 651616661. The next prime is 651616687. The reversal of 651616666 is 666616156.

It is not an unprimeable number, because it can be changed into a prime (651616661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29145 + ... + 46396.

It is an arithmetic number, because the mean of its divisors is an integer number (64588410).

Almost surely, 2^651616666 is an apocalyptic number.

651616666 is a deficient number, since it is larger than the sum of its proper divisors (381797894).

651616666 is a wasteful number, since it uses less digits than its factorization.

651616666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75789.

The product of its digits is 233280, while the sum is 43.

The square root of 651616666 is about 25526.7833069504. The cubic root of 651616666 is about 866.9566745102.

The spelling of 651616666 in words is "six hundred fifty-one million, six hundred sixteen thousand, six hundred sixty-six".