61818393 has 32 divisors (see below), whose sum is σ = 102301696. Its totient is φ = 32332608.

The previous prime is 61818389. The next prime is 61818431. The reversal of 61818393 is 39381816.

It is not a de Polignac number, because 61818393 - 2² = 61818389 is a prime.

It is a super-3 number, since 3×61818393³ (a number of 24 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (61818353) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 33780 + ... + 35562.

It is an arithmetic number, because the mean of its divisors is an integer number (3196928).

Almost surely, 2^61818393 is an apocalyptic number.

It is an amenable number.

61818393 is a deficient number, since it is larger than the sum of its proper divisors (40483303).

61818393 is a wasteful number, since it uses less digits than its factorization.

61818393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1933.

The product of its digits is 31104, while the sum is 39.

The square root of 61818393 is about 7862.4673608226. The cubic root of 61818393 is about 395.4023417367.

The spelling of 61818393 in words is "sixty-one million, eight hundred eighteen thousand, three hundred ninety-three".