61630191 has 72 divisors (see below), whose sum is σ = 110260800. Its totient is φ = 33022080.

The previous prime is 61630187. The next prime is 61630199. The reversal of 61630191 is 19103616.

61630191 is a `hidden beast` number, since 616 + 30 + 19 + 1 = 666.

It is not a de Polignac number, because 61630191 - 2² = 61630187 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61630199) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 780090 + ... + 780168.

It is an arithmetic number, because the mean of its divisors is an integer number (1531400).

Almost surely, 2^61630191 is an apocalyptic number.

61630191 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

61630191 is a deficient number, since it is larger than the sum of its proper divisors (48630609).

61630191 is a wasteful number, since it uses less digits than its factorization.

61630191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189 (or 179 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 61630191 is about 7850.4898573274. The cubic root of 61630191 is about 395.0006751043. Note that the first 3 decimals are identical.

The spelling of 61630191 in words is "sixty-one million, six hundred thirty thousand, one hundred ninety-one".