7981381 has 8 divisors (see below), whose sum is σ = 8679960. Its totient is φ = 7308288.

The previous prime is 7981339. The next prime is 7981397. The reversal of 7981381 is 1831897.

It can be written as a sum of positive squares in 4 ways, for example, as 2149156 + 5832225 = 1466^2 + 2415^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7981381 is a prime.

It is a super-2 number, since 2×7981381² = 127404885334322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 7981381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7981321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5716 + ... + 6973.

It is an arithmetic number, because the mean of its divisors is an integer number (1084995).

Almost surely, 2^7981381 is an apocalyptic number.

It is an amenable number.

7981381 is a deficient number, since it is larger than the sum of its proper divisors (698579).

7981381 is a wasteful number, since it uses less digits than its factorization.

7981381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12743.

The product of its digits is 12096, while the sum is 37.

The square root of 7981381 is about 2825.1338021411. The cubic root of 7981381 is about 199.8447211402.

The spelling of 7981381 in words is "seven million, nine hundred eighty-one thousand, three hundred eighty-one".