690881 has 4 divisors (see below), whose sum is σ = 706992. Its totient is φ = 674772.

The previous prime is 690871. The next prime is 690887. The reversal of 690881 is 188096.

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 690881 - 2⁶ = 690817 is a prime.

It is a super-2 number, since 2×690881² = 954633112322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (690887) 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, 7991 + ... + 8076.

It is an arithmetic number, because the mean of its divisors is an integer number (176748).

2⁶⁹⁰⁸⁸¹ is an apocalyptic number.

It is an amenable number.

690881 is a deficient number, since it is larger than the sum of its proper divisors (16111).

690881 is a wasteful number, since it uses less digits than its factorization.

690881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16110.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 690881 is about 831.1925168094. The cubic root of 690881 is about 88.4031519525.

The spelling of 690881 in words is "six hundred ninety thousand, eight hundred eighty-one".