61812831 has 4 divisors (see below), whose sum is σ = 82417112. Its totient is φ = 41208552.

The previous prime is 61812797. The next prime is 61812841. The reversal of 61812831 is 13821816.

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

It is not a de Polignac number, because 61812831 - 2⁹ = 61812319 is a prime.

It is a super-2 number, since 2×61812831² = 7641652152469122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61812841) 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, 10302136 + ... + 10302141.

It is an arithmetic number, because the mean of its divisors is an integer number (20604278).

Almost surely, 2^61812831 is an apocalyptic number.

61812831 is a deficient number, since it is larger than the sum of its proper divisors (20604281).

61812831 is a wasteful number, since it uses less digits than its factorization.

61812831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20604280.

The product of its digits is 2304, while the sum is 30.

The square root of 61812831 is about 7862.1136471053. The cubic root of 61812831 is about 395.3904828401.

The spelling of 61812831 in words is "sixty-one million, eight hundred twelve thousand, eight hundred thirty-one".