61668539 has 2 divisors, whose sum is σ = 61668540. Its totient is φ = 61668538.

The previous prime is 61668527. The next prime is 61668553. The reversal of 61668539 is 93586616.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61668539 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61668539.

It is not a weakly prime, because it can be changed into another prime (61668599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30834269 + 30834270.

It is an arithmetic number, because the mean of its divisors is an integer number (30834270).

Almost surely, 2^61668539 is an apocalyptic number.

61668539 is a deficient number, since it is larger than the sum of its proper divisors (1).

61668539 is an equidigital number, since it uses as much as digits as its factorization.

61668539 is an evil number, because the sum of its binary digits is even.

The product of its digits is 233280, while the sum is 44.

The square root of 61668539 is about 7852.9318728740. The cubic root of 61668539 is about 395.0825848794.

The spelling of 61668539 in words is "sixty-one million, six hundred sixty-eight thousand, five hundred thirty-nine".