651606661606 has 4 divisors (see below), whose sum is σ = 977409992412. Its totient is φ = 325803330802.

The previous prime is 651606661597. The next prime is 651606661609. The reversal of 651606661606 is 606166606156.

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

It is a self number, because there is not a number n which added to its sum of digits gives 651606661606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (651606661609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 162901665400 + ... + 162901665403.

It is an arithmetic number, because the mean of its divisors is an integer number (244352498103).

Almost surely, 2^651606661606 is an apocalyptic number.

651606661606 is a deficient number, since it is larger than the sum of its proper divisors (325803330806).

651606661606 is a wasteful number, since it uses less digits than its factorization.

651606661606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 325803330805.

The product of its (nonzero) digits is 1399680, while the sum is 49.

The spelling of 651606661606 in words is "six hundred fifty-one billion, six hundred six million, six hundred sixty-one thousand, six hundred six".