61831989 has 12 divisors (see below), whose sum is σ = 89778156. Its totient is φ = 41006592.

The previous prime is 61831963. The next prime is 61831999. The reversal of 61831989 is 98913816.

It can be written as a sum of positive squares in 2 ways, for example, as 10595025 + 51236964 = 3255^2 + 7158^2 .

It is not a de Polignac number, because 61831989 - 2¹² = 61827893 is a prime.

It is a super-2 number, since 2×61831989² = 7646389727392242, which contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61831919) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16062 + ... + 19535.

It is an arithmetic number, because the mean of its divisors is an integer number (7481513).

Almost surely, 2^61831989 is an apocalyptic number.

It is an amenable number.

61831989 is a deficient number, since it is larger than the sum of its proper divisors (27946167).

61831989 is a wasteful number, since it uses less digits than its factorization.

61831989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35796 (or 35793 counting only the distinct ones).

The product of its digits is 93312, while the sum is 45.

The square root of 61831989 is about 7863.3319273702. The cubic root of 61831989 is about 395.4313271563.

The spelling of 61831989 in words is "sixty-one million, eight hundred thirty-one thousand, nine hundred eighty-nine".