61663191 has 16 divisors (see below), whose sum is σ = 83453664. Its totient is φ = 40495104.

The previous prime is 61663187. The next prime is 61663211. The reversal of 61663191 is 19136616.

It is not a de Polignac number, because 61663191 - 2² = 61663187 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61663111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 90745 + ... + 91421.

It is an arithmetic number, because the mean of its divisors is an integer number (5215854).

Almost surely, 2^61663191 is an apocalyptic number.

61663191 is a deficient number, since it is larger than the sum of its proper divisors (21790473).

61663191 is a wasteful number, since it uses less digits than its factorization.

61663191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1090.

The product of its digits is 5832, while the sum is 33.

The square root of 61663191 is about 7852.5913557246. The cubic root of 61663191 is about 395.0711638059.

The spelling of 61663191 in words is "sixty-one million, six hundred sixty-three thousand, one hundred ninety-one".