7981913 has 4 divisors (see below), whose sum is σ = 7989120. Its totient is φ = 7974708.

The previous prime is 7981907. The next prime is 7981927. The reversal of 7981913 is 3191897.

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.

It is a cyclic number.

It is not a de Polignac number, because 7981913 - 2¹² = 7977817 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7981013) 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, 1553 + ... + 4286.

It is an arithmetic number, because the mean of its divisors is an integer number (1997280).

Almost surely, 2^7981913 is an apocalyptic number.

It is an amenable number.

7981913 is a deficient number, since it is larger than the sum of its proper divisors (7207).

7981913 is a wasteful number, since it uses less digits than its factorization.

7981913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7206.

The product of its digits is 13608, while the sum is 38.

The square root of 7981913 is about 2825.2279554047. The cubic root of 7981913 is about 199.8491612670.

It can be divided in two parts, 7981 and 913, that multiplied together give a triangular number (7286653 = T₃₈₁₇).

The spelling of 7981913 in words is "seven million, nine hundred eighty-one thousand, nine hundred thirteen".