61309687 has 2 divisors, whose sum is σ = 61309688. Its totient is φ = 61309686.

The previous prime is 61309621. The next prime is 61309709. The reversal of 61309687 is 78690316.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61309687 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61309487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30654843 + 30654844.

It is an arithmetic number, because the mean of its divisors is an integer number (30654844).

Almost surely, 2^61309687 is an apocalyptic number.

61309687 is a deficient number, since it is larger than the sum of its proper divisors (1).

61309687 is an equidigital number, since it uses as much as digits as its factorization.

61309687 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 61309687 is about 7830.0502552666. The cubic root of 61309687 is about 394.3147591713.

The spelling of 61309687 in words is "sixty-one million, three hundred nine thousand, six hundred eighty-seven".