690278728 has 8 divisors (see below), whose sum is σ = 1294272630. Its totient is φ = 345139360.

The previous prime is 690278723. The next prime is 690278753. The reversal of 690278728 is 827872096.

It can be written as a sum of positive squares in only one way, i.e., 562543524 + 127735204 = 23718^2 + 11302^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (690278723) 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 as a sum of consecutive naturals, namely, 43142413 + ... + 43142428.

Almost surely, 2^690278728 is an apocalyptic number.

It is an amenable number.

690278728 is a deficient number, since it is larger than the sum of its proper divisors (603993902).

690278728 is a wasteful number, since it uses less digits than its factorization.

690278728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86284847 (or 86284843 counting only the distinct ones).

The product of its (nonzero) digits is 677376, while the sum is 49.

The square root of 690278728 is about 26273.1560342491. The cubic root of 690278728 is about 883.7745615152.

The spelling of 690278728 in words is "six hundred ninety million, two hundred seventy-eight thousand, seven hundred twenty-eight".