697981 has 4 divisors (see below), whose sum is σ = 728352. Its totient is φ = 667612.

The previous prime is 697979. The next prime is 697993. The reversal of 697981 is 189796.

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 697981 - 2¹ = 697979 is a prime.

It is a super-2 number, since 2×697981² = 974354952722, which contains 22 as substring.

It is a Duffinian number.

697981 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (697951) 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, 15151 + ... + 15196.

It is an arithmetic number, because the mean of its divisors is an integer number (182088).

2⁶⁹⁷⁹⁸¹ is an apocalyptic number.

It is an amenable number.

697981 is a deficient number, since it is larger than the sum of its proper divisors (30371).

697981 is a wasteful number, since it uses less digits than its factorization.

697981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30370.

The product of its digits is 27216, while the sum is 40.

The square root of 697981 is about 835.4525719632. The cubic root of 697981 is about 88.7049523419.

The spelling of 697981 in words is "six hundred ninety-seven thousand, nine hundred eighty-one".