61691601 has 4 divisors (see below), whose sum is σ = 82255472. Its totient is φ = 41127732.

The previous prime is 61691587. The next prime is 61691611. The reversal of 61691601 is 10619616.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 61691601 - 2⁷ = 61691473 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61691611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10281931 + ... + 10281936.

It is an arithmetic number, because the mean of its divisors is an integer number (20563868).

Almost surely, 2^61691601 is an apocalyptic number.

It is an amenable number.

61691601 is a deficient number, since it is larger than the sum of its proper divisors (20563871).

61691601 is a wasteful number, since it uses less digits than its factorization.

61691601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20563870.

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

The square root of 61691601 is about 7854.4001044001. The cubic root of 61691601 is about 395.1318280276.

The spelling of 61691601 in words is "sixty-one million, six hundred ninety-one thousand, six hundred one".