61491983 has 8 divisors (see below), whose sum is σ = 71468160. Its totient is φ = 51813720.

The previous prime is 61491973. The next prime is 61492051. The reversal of 61491983 is 38919416.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 61491983 - 2¹⁶ = 61426447 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61491983.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61491973) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74033 + ... + 74858.

It is an arithmetic number, because the mean of its divisors is an integer number (8933520).

Almost surely, 2^61491983 is an apocalyptic number.

61491983 is a deficient number, since it is larger than the sum of its proper divisors (9976177).

61491983 is a wasteful number, since it uses less digits than its factorization.

61491983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148957.

The product of its digits is 46656, while the sum is 41.

The square root of 61491983 is about 7841.6824087692. The cubic root of 61491983 is about 394.7051862012.

The spelling of 61491983 in words is "sixty-one million, four hundred ninety-one thousand, nine hundred eighty-three".