61491 has 8 divisors (see below), whose sum is σ = 83200. Its totient is φ = 40392.

The previous prime is 61487. The next prime is 61493. The reversal of 61491 is 19416.

61491 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 61491 - 2² = 61487 is a prime.

It is a super-2 number, since 2×61491² = 7562286162, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a nialpdrome in base 11.

It is a zygodrome in base 2.

It is not an unprimeable number, because it can be changed into a prime (61493) 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, 210 + ... + 408.

It is an arithmetic number, because the mean of its divisors is an integer number (10400).

2⁶¹⁴⁹¹ is an apocalyptic number.

61491 is a deficient number, since it is larger than the sum of its proper divisors (21709).

61491 is a wasteful number, since it uses less digits than its factorization.

61491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305.

The product of its digits is 216, while the sum is 21.

The square root of 61491 is about 247.9737889375. The cubic root of 61491 is about 39.4703082961.

The spelling of 61491 in words is "sixty-one thousand, four hundred ninety-one".