5671981 has 8 divisors (see below), whose sum is σ = 6640704. Its totient is φ = 4742880.

The previous prime is 5671979. The next prime is 5671987. The reversal of 5671981 is 1891765.

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

It is not a de Polignac number, because 5671981 - 2¹ = 5671979 is a prime.

It is a super-2 number, since 2×5671981² = 64342736928722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 5671981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5671987) 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 7 ways as a sum of consecutive naturals, for example, 9595 + ... + 10168.

It is an arithmetic number, because the mean of its divisors is an integer number (830088).

Almost surely, 2^5671981 is an apocalyptic number.

It is an amenable number.

5671981 is a deficient number, since it is larger than the sum of its proper divisors (968723).

5671981 is a wasteful number, since it uses less digits than its factorization.

5671981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19811.

The product of its digits is 15120, while the sum is 37.

The square root of 5671981 is about 2381.5921145318. The cubic root of 5671981 is about 178.3384232008.

The spelling of 5671981 in words is "five million, six hundred seventy-one thousand, nine hundred eighty-one".