61491408 has 40 divisors (see below), whose sum is σ = 173295456. Its totient is φ = 18633600.

The previous prime is 61491401. The next prime is 61491413. The reversal of 61491408 is 80419416.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61491401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57703 + ... + 58758.

Almost surely, 2^61491408 is an apocalyptic number.

It is an amenable number.

61491408 is an abundant number, since it is smaller than the sum of its proper divisors (111804048).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61491408 is a wasteful number, since it uses less digits than its factorization.

61491408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116483 (or 116477 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 61491408 is about 7841.6457456327. The cubic root of 61491408 is about 394.7039559260.

It can be divided in two parts, 6149 and 1408, that added together give a palindrome (7557).

The spelling of 61491408 in words is "sixty-one million, four hundred ninety-one thousand, four hundred eight".