61129209 has 8 divisors (see below), whose sum is σ = 81577152. Its totient is φ = 40717040.

The previous prime is 61129171. The next prime is 61129253. The reversal of 61129209 is 90292116.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61129209 - 2²⁰ = 60080633 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61129279) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4662 + ... + 11999.

It is an arithmetic number, because the mean of its divisors is an integer number (10197144).

Almost surely, 2^61129209 is an apocalyptic number.

It is an amenable number.

61129209 is a deficient number, since it is larger than the sum of its proper divisors (20447943).

61129209 is a wasteful number, since it uses less digits than its factorization.

61129209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17887.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 61129209 is about 7818.5170588802. The cubic root of 61129209 is about 393.9274626614.

The spelling of 61129209 in words is "sixty-one million, one hundred twenty-nine thousand, two hundred nine".