690642217 has 4 divisors (see below), whose sum is σ = 691261636. Its totient is φ = 690022800.

The previous prime is 690642209. The next prime is 690642233. The reversal of 690642217 is 712246096.

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 81342361 + 609299856 = 9019^2 + 24684^2 .

It is a cyclic number.

It is not a de Polignac number, because 690642217 - 2³ = 690642209 is a prime.

It is a super-5 number, since 5×690642217⁵ (a number of 45 digits) contains 55555 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (690642257) 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, 308034 + ... + 310267.

It is an arithmetic number, because the mean of its divisors is an integer number (172815409).

Almost surely, 2^690642217 is an apocalyptic number.

It is an amenable number.

690642217 is a deficient number, since it is larger than the sum of its proper divisors (619419).

690642217 is a wasteful number, since it uses less digits than its factorization.

690642217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 619418.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 690642217 is about 26280.0726216653. The cubic root of 690642217 is about 883.9296611622.

The spelling of 690642217 in words is "six hundred ninety million, six hundred forty-two thousand, two hundred seventeen".