690849221 has 8 divisors (see below), whose sum is σ = 708049944. Its totient is φ = 673665280.

The previous prime is 690849199. The next prime is 690849251. The reversal of 690849221 is 122948096.

It can be written as a sum of positive squares in 4 ways, for example, as 81450625 + 609398596 = 9025^2 + 24686^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 690849221 - 2⁶ = 690849157 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (690849251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137465 + ... + 142401.

It is an arithmetic number, because the mean of its divisors is an integer number (88506243).

Almost surely, 2^690849221 is an apocalyptic number.

It is an amenable number.

690849221 is a deficient number, since it is larger than the sum of its proper divisors (17200723).

690849221 is a wasteful number, since it uses less digits than its factorization.

690849221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8391.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 690849221 is about 26284.0107479814. The cubic root of 690849221 is about 884.0179648179.

The spelling of 690849221 in words is "six hundred ninety million, eight hundred forty-nine thousand, two hundred twenty-one".