166618651 has 2 divisors, whose sum is σ = 166618652. Its totient is φ = 166618650.

The previous prime is 166618609. The next prime is 166618709. The reversal of 166618651 is 156816661.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (156816661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166618651 - 2⁷ = 166618523 is a prime.

It is a super-2 number, since 2×166618651² = 55523549722119602, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (166618051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83309325 + 83309326.

It is an arithmetic number, because the mean of its divisors is an integer number (83309326).

Almost surely, 2^166618651 is an apocalyptic number.

166618651 is a deficient number, since it is larger than the sum of its proper divisors (1).

166618651 is an equidigital number, since it uses as much as digits as its factorization.

166618651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 40.

The square root of 166618651 is about 12908.0847146275. The cubic root of 166618651 is about 550.2683549938.

The spelling of 166618651 in words is "one hundred sixty-six million, six hundred eighteen thousand, six hundred fifty-one".