69981 has 4 divisors (see below), whose sum is σ = 93312. Its totient is φ = 46652.

The previous prime is 69959. The next prime is 69991. The reversal of 69981 is 18996.

It is a happy number.

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 69981 - 2¹¹ = 67933 is a prime.

It is a super-2 number, since 2×69981² = 9794680722, which contains 22 as substring.

It is a D-number.

It is a plaindrome in base 16.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 69981.

It is not an unprimeable number, because it can be changed into a prime (69911) 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, 11661 + ... + 11666.

It is an arithmetic number, because the mean of its divisors is an integer number (23328).

2⁶⁹⁹⁸¹ is an apocalyptic number.

It is an amenable number.

69981 is a deficient number, since it is larger than the sum of its proper divisors (23331).

69981 is a wasteful number, since it uses less digits than its factorization.

69981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23330.

The product of its digits is 3888, while the sum is 33.

The square root of 69981 is about 264.5392220447. The cubic root of 69981 is about 41.2091238787.

Multiplying 69981 by its product of digits (3888), we get a triangular number (272086128 = T₂₃₃₂₇).

It can be divided in two parts, 699 and 81, that added together give a triangular number (780 = T₃₉).

The spelling of 69981 in words is "sixty-nine thousand, nine hundred eighty-one".