266442640 has 40 divisors (see below), whose sum is σ = 620158968. Its totient is φ = 106460160.

The previous prime is 266442637. The next prime is 266442677. The reversal of 266442640 is 46244662.

It can be written as a sum of positive squares in 4 ways, for example, as 6330256 + 260112384 = 2516^2 + 16128^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 266442596 and 266442605.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 138324 + ... + 140236.

Almost surely, 2^266442640 is an apocalyptic number.

266442640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

266442640 is an abundant number, since it is smaller than the sum of its proper divisors (353716328).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

266442640 is a wasteful number, since it uses less digits than its factorization.

266442640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3667 (or 3661 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 34.

The square root of 266442640 is about 16323.0707895298. The cubic root of 266442640 is about 643.4792930981.

The spelling of 266442640 in words is "two hundred sixty-six million, four hundred forty-two thousand, six hundred forty".