61387491 has 16 divisors (see below), whose sum is σ = 89445888. Its totient is φ = 37140000.

The previous prime is 61387481. The next prime is 61387507. The reversal of 61387491 is 19478316.

It is not a de Polignac number, because 61387491 - 2¹⁹ = 60863203 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61387441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23545 + ... + 26021.

It is an arithmetic number, because the mean of its divisors is an integer number (5590368).

Almost surely, 2^61387491 is an apocalyptic number.

61387491 is a deficient number, since it is larger than the sum of its proper divisors (28058397).

61387491 is a wasteful number, since it uses less digits than its factorization.

61387491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3242.

The product of its digits is 36288, while the sum is 39.

The square root of 61387491 is about 7835.0169750933. The cubic root of 61387491 is about 394.4814881092.

The spelling of 61387491 in words is "sixty-one million, three hundred eighty-seven thousand, four hundred ninety-one".