61813919 has 12 divisors (see below), whose sum is σ = 64104552. Its totient is φ = 59598000.

The previous prime is 61813909. The next prime is 61813943. The reversal of 61813919 is 91931816.

It is not a de Polignac number, because 61813919 - 2¹² = 61809823 is a prime.

It is a super-2 number, since 2×61813919² = 7641921164277122, 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 (61813909) 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 11 ways as a sum of consecutive naturals, for example, 186584 + ... + 186914.

It is an arithmetic number, because the mean of its divisors is an integer number (5342046).

Almost surely, 2^61813919 is an apocalyptic number.

61813919 is a deficient number, since it is larger than the sum of its proper divisors (2290633).

61813919 is a wasteful number, since it uses less digits than its factorization.

61813919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 518 (or 475 counting only the distinct ones).

The product of its digits is 11664, while the sum is 38.

The square root of 61813919 is about 7862.1828393901. The cubic root of 61813919 is about 395.3928026515.

The spelling of 61813919 in words is "sixty-one million, eight hundred thirteen thousand, nine hundred nineteen".