61643759 has 2 divisors, whose sum is σ = 61643760. Its totient is φ = 61643758.

The previous prime is 61643741. The next prime is 61643761. The reversal of 61643759 is 95734616.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61643759 - 2¹² = 61639663 is a prime.

Together with 61643761, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61643789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30821879 + 30821880.

It is an arithmetic number, because the mean of its divisors is an integer number (30821880).

Almost surely, 2^61643759 is an apocalyptic number.

61643759 is a deficient number, since it is larger than the sum of its proper divisors (1).

61643759 is an equidigital number, since it uses as much as digits as its factorization.

61643759 is an evil number, because the sum of its binary digits is even.

The product of its digits is 136080, while the sum is 41.

The square root of 61643759 is about 7851.3539596684. The cubic root of 61643759 is about 395.0296596860.

The spelling of 61643759 in words is "sixty-one million, six hundred forty-three thousand, seven hundred fifty-nine".