690421849 has 4 divisors (see below), whose sum is σ = 743531236. Its totient is φ = 637312464.

The previous prime is 690421819. The next prime is 690421859. The reversal of 690421849 is 948124096.

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 392238025 + 298183824 = 19805^2 + 17268^2 .

It is a cyclic number.

It is not a de Polignac number, because 690421849 - 2¹³ = 690413657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (690421819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26554674 + ... + 26554699.

It is an arithmetic number, because the mean of its divisors is an integer number (185882809).

Almost surely, 2^690421849 is an apocalyptic number.

It is an amenable number.

690421849 is a deficient number, since it is larger than the sum of its proper divisors (53109387).

690421849 is a wasteful number, since it uses less digits than its factorization.

690421849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53109386.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 690421849 is about 26275.8796046869. The cubic root of 690421849 is about 883.8356373063.

The spelling of 690421849 in words is "six hundred ninety million, four hundred twenty-one thousand, eight hundred forty-nine".