4993981 has 4 divisors (see below), whose sum is σ = 4999552. Its totient is φ = 4988412.

The previous prime is 4993951. The next prime is 4993987. The reversal of 4993981 is 1893994.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1893994 = 2 ⋅946997.

It is a cyclic number.

It is not a de Polignac number, because 4993981 - 2⁵ = 4993949 is a prime.

It is a super-2 number, since 2×4993981² = 49879692456722, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

4993981 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4993987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1101 + ... + 3346.

It is an arithmetic number, because the mean of its divisors is an integer number (1249888).

Almost surely, 2^4993981 is an apocalyptic number.

It is an amenable number.

4993981 is a deficient number, since it is larger than the sum of its proper divisors (5571).

4993981 is a wasteful number, since it uses less digits than its factorization.

4993981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5570.

The product of its digits is 69984, while the sum is 43.

The square root of 4993981 is about 2234.7216828948. The cubic root of 4993981 is about 170.9289514813.

The spelling of 4993981 in words is "four million, nine hundred ninety-three thousand, nine hundred eighty-one".