61813731 has 16 divisors (see below), whose sum is σ = 95600384. Its totient is φ = 34794144.

The previous prime is 61813729. The next prime is 61813753. The reversal of 61813731 is 13731816.

It is not a de Polignac number, because 61813731 - 2¹ = 61813729 is a prime.

It is a super-2 number, since 2×61813731² = 7641874680280722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61813711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20560 + ... + 23373.

It is an arithmetic number, because the mean of its divisors is an integer number (5975024).

Almost surely, 2^61813731 is an apocalyptic number.

61813731 is a deficient number, since it is larger than the sum of its proper divisors (33786653).

61813731 is a wasteful number, since it uses less digits than its factorization.

61813731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44010.

The product of its digits is 3024, while the sum is 30.

The square root of 61813731 is about 7862.1708834138. The cubic root of 61813731 is about 395.3924018037.

The spelling of 61813731 in words is "sixty-one million, eight hundred thirteen thousand, seven hundred thirty-one".