61811409 has 32 divisors (see below), whose sum is σ = 93312000. Its totient is φ = 36071360.

The previous prime is 61811381. The next prime is 61811411. The reversal of 61811409 is 90411816.

It is a cyclic number.

It is not a de Polignac number, because 61811409 - 2⁵ = 61811377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61811459) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 102892 + ... + 103490.

It is an arithmetic number, because the mean of its divisors is an integer number (2916000).

Almost surely, 2^61811409 is an apocalyptic number.

It is an amenable number.

61811409 is a deficient number, since it is larger than the sum of its proper divisors (31500591).

61811409 is a wasteful number, since it uses less digits than its factorization.

61811409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 725.

The product of its (nonzero) digits is 1728, while the sum is 30.

The square root of 61811409 is about 7862.0232128887. The cubic root of 61811409 is about 395.3874508398.

The spelling of 61811409 in words is "sixty-one million, eight hundred eleven thousand, four hundred nine".