6989981 has 4 divisors (see below), whose sum is σ = 7138752. Its totient is φ = 6841212.

The previous prime is 6989963. The next prime is 6989987. The reversal of 6989981 is 1899896.

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.

It is a cyclic number.

It is not a de Polignac number, because 6989981 - 2¹⁴ = 6973597 is a prime.

It is a super-2 number, since 2×6989981² = 97719668760722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6989987) 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, 74315 + ... + 74408.

It is an arithmetic number, because the mean of its divisors is an integer number (1784688).

Almost surely, 2^6989981 is an apocalyptic number.

It is an amenable number.

6989981 is a deficient number, since it is larger than the sum of its proper divisors (148771).

6989981 is a wasteful number, since it uses less digits than its factorization.

6989981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148770.

The product of its digits is 279936, while the sum is 50.

The square root of 6989981 is about 2643.8572200480. The cubic root of 6989981 is about 191.2018096647.

The spelling of 6989981 in words is "six million, nine hundred eighty-nine thousand, nine hundred eighty-one".