690121 has 4 divisors (see below), whose sum is σ = 692244. Its totient is φ = 688000.

The previous prime is 690119. The next prime is 690127. The reversal of 690121 is 121096.

690121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 622521 + 67600 = 789^2 + 260^2 .

It is a cyclic number.

It is not a de Polignac number, because 690121 - 2¹ = 690119 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (690127) 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, 460 + ... + 1261.

It is an arithmetic number, because the mean of its divisors is an integer number (173061).

2⁶⁹⁰¹²¹ is an apocalyptic number.

It is an amenable number.

690121 is a deficient number, since it is larger than the sum of its proper divisors (2123).

690121 is a wasteful number, since it uses less digits than its factorization.

690121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2122.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 690121 is about 830.7352165401. The cubic root of 690121 is about 88.3707242519.

The spelling of 690121 in words is "six hundred ninety thousand, one hundred twenty-one".