689183921 has 4 divisors (see below), whose sum is σ = 689961792. Its totient is φ = 688406052.

The previous prime is 689183881. The next prime is 689183923. The reversal of 689183921 is 129381986.

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, and also an emirpimes, since its reverse is a distinct semiprime: 129381986 = 2 ⋅64690993.

It is a cyclic number.

It is not a de Polignac number, because 689183921 - 2¹⁸ = 688921777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (689183923) 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, 387605 + ... + 389378.

It is an arithmetic number, because the mean of its divisors is an integer number (172490448).

Almost surely, 2^689183921 is an apocalyptic number.

It is an amenable number.

689183921 is a deficient number, since it is larger than the sum of its proper divisors (777871).

689183921 is an equidigital number, since it uses as much as digits as its factorization.

689183921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 777870.

The product of its digits is 186624, while the sum is 47.

The square root of 689183921 is about 26252.3126790765. The cubic root of 689183921 is about 883.3070814871.

The spelling of 689183921 in words is "six hundred eighty-nine million, one hundred eighty-three thousand, nine hundred twenty-one".