1205266640 has 40 divisors (see below), whose sum is σ = 2855127528. Its totient is φ = 473008640.

The previous prime is 1205266619. The next prime is 1205266649. The reversal of 1205266640 is 466625021.

It can be written as a sum of positive squares in 4 ways, for example, as 168169024 + 1037097616 = 12968^2 + 32204^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 1205266597 and 1205266606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1205266649) 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, 137891 + ... + 146370.

Almost surely, 2^1205266640 is an apocalyptic number.

1205266640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1205266640 is an abundant number, since it is smaller than the sum of its proper divisors (1649860888).

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

1205266640 is a wasteful number, since it uses less digits than its factorization.

1205266640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284327 (or 284321 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 1205266640 is about 34716.9503268936. The cubic root of 1205266640 is about 1064.2109226261.

The spelling of 1205266640 in words is "one billion, two hundred five million, two hundred sixty-six thousand, six hundred forty".