61218993 has 16 divisors (see below), whose sum is σ = 89839296. Its totient is φ = 36771840.

The previous prime is 61218973. The next prime is 61219003. The reversal of 61218993 is 39981216.

It is not a de Polignac number, because 61218993 - 2¹² = 61214897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61218943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4480 + ... + 11937.

It is an arithmetic number, because the mean of its divisors is an integer number (5614956).

Almost surely, 2^61218993 is an apocalyptic number.

It is an amenable number.

61218993 is a deficient number, since it is larger than the sum of its proper divisors (28620303).

61218993 is a wasteful number, since it uses less digits than its factorization.

61218993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16544.

The product of its digits is 23328, while the sum is 39.

The square root of 61218993 is about 7824.2567059114. The cubic root of 61218993 is about 394.1202296552.

The spelling of 61218993 in words is "sixty-one million, two hundred eighteen thousand, nine hundred ninety-three".