61588991 has 4 divisors (see below), whose sum is σ = 61643112. Its totient is φ = 61534872.

The previous prime is 61588981. The next prime is 61589023. The reversal of 61588991 is 19988516.

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

It is a cyclic number.

It is not a de Polignac number, because 61588991 - 2⁶ = 61588927 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 (61588921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25316 + ... + 27641.

It is an arithmetic number, because the mean of its divisors is an integer number (15410778).

Almost surely, 2^61588991 is an apocalyptic number.

61588991 is a deficient number, since it is larger than the sum of its proper divisors (54121).

61588991 is a wasteful number, since it uses less digits than its factorization.

61588991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54120.

The product of its digits is 155520, while the sum is 47.

The square root of 61588991 is about 7847.8653785600. The cubic root of 61588991 is about 394.9126357018.

The spelling of 61588991 in words is "sixty-one million, five hundred eighty-eight thousand, nine hundred ninety-one".