61709987 has 2 divisors, whose sum is σ = 61709988. Its totient is φ = 61709986.

The previous prime is 61709971. The next prime is 61710001. The reversal of 61709987 is 78990716.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61709987 - 2⁴ = 61709971 is a prime.

It is not a weakly prime, because it can be changed into another prime (61702987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30854993 + 30854994.

It is an arithmetic number, because the mean of its divisors is an integer number (30854994).

Almost surely, 2^61709987 is an apocalyptic number.

61709987 is a deficient number, since it is larger than the sum of its proper divisors (1).

61709987 is an equidigital number, since it uses as much as digits as its factorization.

61709987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 190512, while the sum is 47.

The square root of 61709987 is about 7855.5704439589. The cubic root of 61709987 is about 395.1710779529.

The spelling of 61709987 in words is "sixty-one million, seven hundred nine thousand, nine hundred eighty-seven".