61689509 has 16 divisors (see below), whose sum is σ = 72223488. Its totient is φ = 51597312.

The previous prime is 61689499. The next prime is 61689527. The reversal of 61689509 is 90598616.

It is a cyclic number.

It is not a de Polignac number, because 61689509 - 2⁸ = 61689253 is a prime.

It is a super-2 number, since 2×61689509² = 7611191041322162, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 61689509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61689569) 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, 95024 + ... + 95670.

It is an arithmetic number, because the mean of its divisors is an integer number (4513968).

Almost surely, 2^61689509 is an apocalyptic number.

It is an amenable number.

61689509 is a deficient number, since it is larger than the sum of its proper divisors (10533979).

61689509 is a wasteful number, since it uses less digits than its factorization.

61689509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 964.

The product of its (nonzero) digits is 116640, while the sum is 44.

The square root of 61689509 is about 7854.2669295104. The cubic root of 61689509 is about 395.1273615897.

The spelling of 61689509 in words is "sixty-one million, six hundred eighty-nine thousand, five hundred nine".