61161997 has 4 divisors (see below), whose sum is σ = 65866780. Its totient is φ = 56457216.

The previous prime is 61161983. The next prime is 61162009. The reversal of 61161997 is 79916116.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21585316 + 39576681 = 4646^2 + 6291^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61161997 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 (61161097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2352372 + ... + 2352397.

It is an arithmetic number, because the mean of its divisors is an integer number (16466695).

Almost surely, 2^61161997 is an apocalyptic number.

It is an amenable number.

61161997 is a deficient number, since it is larger than the sum of its proper divisors (4704783).

61161997 is a wasteful number, since it uses less digits than its factorization.

61161997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4704782.

The product of its digits is 20412, while the sum is 40.

The square root of 61161997 is about 7820.6135948530. The cubic root of 61161997 is about 393.9978806348.

The spelling of 61161997 in words is "sixty-one million, one hundred sixty-one thousand, nine hundred ninety-seven".