61709989 has 16 divisors (see below), whose sum is σ = 70761600. Its totient is φ = 53268160.

The previous prime is 61709987. The next prime is 61710001. The reversal of 61709989 is 98990716.

It is not a de Polignac number, because 61709989 - 2¹ = 61709987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61709987) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36879 + ... + 38515.

It is an arithmetic number, because the mean of its divisors is an integer number (4422600).

Almost surely, 2^61709989 is an apocalyptic number.

It is an amenable number.

61709989 is a deficient number, since it is larger than the sum of its proper divisors (9051611).

61709989 is a wasteful number, since it uses less digits than its factorization.

61709989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1820.

The product of its (nonzero) digits is 244944, while the sum is 49.

The square root of 61709989 is about 7855.5705712571. The cubic root of 61709989 is about 395.1710822220.

The spelling of 61709989 in words is "sixty-one million, seven hundred nine thousand, nine hundred eighty-nine".