61791813 has 24 divisors (see below), whose sum is σ = 92660568. Its totient is φ = 39647232.

The previous prime is 61791811. The next prime is 61791881. The reversal of 61791813 is 31819716.

It can be written as a sum of positive squares in 4 ways, for example, as 32012964 + 29778849 = 5658^2 + 5457^2 .

It is not a de Polignac number, because 61791813 - 2¹ = 61791811 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61791811) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31345 + ... + 33257.

It is an arithmetic number, because the mean of its divisors is an integer number (3860857).

Almost surely, 2^61791813 is an apocalyptic number.

It is an amenable number.

61791813 is a deficient number, since it is larger than the sum of its proper divisors (30868755).

61791813 is a wasteful number, since it uses less digits than its factorization.

61791813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2053 (or 2050 counting only the distinct ones).

The product of its digits is 9072, while the sum is 36.

The square root of 61791813 is about 7860.7768700046. The cubic root of 61791813 is about 395.3456633470.

The spelling of 61791813 in words is "sixty-one million, seven hundred ninety-one thousand, eight hundred thirteen".