61664651 has 2 divisors, whose sum is σ = 61664652. Its totient is φ = 61664650.

The previous prime is 61664579. The next prime is 61664653. The reversal of 61664651 is 15646616.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61664651 - 2¹⁰ = 61663627 is a prime.

It is a Sophie Germain prime.

Together with 61664653, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (61664653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30832325 + 30832326.

It is an arithmetic number, because the mean of its divisors is an integer number (30832326).

Almost surely, 2^61664651 is an apocalyptic number.

61664651 is a deficient number, since it is larger than the sum of its proper divisors (1).

61664651 is an equidigital number, since it uses as much as digits as its factorization.

61664651 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25920, while the sum is 35.

The square root of 61664651 is about 7852.6843181170. The cubic root of 61664651 is about 395.0742818160.

The spelling of 61664651 in words is "sixty-one million, six hundred sixty-four thousand, six hundred fifty-one".