61072813 has 4 divisors (see below), whose sum is σ = 61112380. Its totient is φ = 61033248.

The previous prime is 61072799. The next prime is 61072853. The reversal of 61072813 is 31827016.

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 29735209 + 31337604 = 5453^2 + 5598^2 .

It is a cyclic number.

It is not a de Polignac number, because 61072813 - 2⁹ = 61072301 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 (61072853) 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, 17370 + ... + 20587.

It is an arithmetic number, because the mean of its divisors is an integer number (15278095).

Almost surely, 2^61072813 is an apocalyptic number.

It is an amenable number.

61072813 is a deficient number, since it is larger than the sum of its proper divisors (39567).

61072813 is a wasteful number, since it uses less digits than its factorization.

61072813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39566.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 61072813 is about 7814.9096603864. The cubic root of 61072813 is about 393.8062834467.

Adding to 61072813 its reverse (31827016), we get a palindrome (92899829).

The spelling of 61072813 in words is "sixty-one million, seventy-two thousand, eight hundred thirteen".