61843813 has 4 divisors (see below), whose sum is σ = 62857708. Its totient is φ = 60829920.

The previous prime is 61843811. The next prime is 61843819. The reversal of 61843813 is 31834816.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6980164 + 54863649 = 2642^2 + 7407^2 .

It is a cyclic number.

It is not a de Polignac number, because 61843813 - 2¹ = 61843811 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61843811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 506856 + ... + 506977.

It is an arithmetic number, because the mean of its divisors is an integer number (15714427).

Almost surely, 2^61843813 is an apocalyptic number.

It is an amenable number.

61843813 is a deficient number, since it is larger than the sum of its proper divisors (1013895).

61843813 is a wasteful number, since it uses less digits than its factorization.

61843813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1013894.

The product of its digits is 13824, while the sum is 34.

The square root of 61843813 is about 7864.0837355664. The cubic root of 61843813 is about 395.4565313808.

The spelling of 61843813 in words is "sixty-one million, eight hundred forty-three thousand, eight hundred thirteen".