265402640 has 80 divisors (see below), whose sum is σ = 687813120. Its totient is φ = 94648320.

The previous prime is 265402639. The next prime is 265402651. The reversal of 265402640 is 46204562.

265402640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×265402640² = 140877122637939200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20705 + ... + 30975.

It is an arithmetic number, because the mean of its divisors is an integer number (8597664).

Almost surely, 2^265402640 is an apocalyptic number.

265402640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 265402640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (343906560).

265402640 is an abundant number, since it is smaller than the sum of its proper divisors (422410480).

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

265402640 is a wasteful number, since it uses less digits than its factorization.

265402640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10320 (or 10314 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 29.

The square root of 265402640 is about 16291.1828913680. The cubic root of 265402640 is about 642.6409749854.

The spelling of 265402640 in words is "two hundred sixty-five million, four hundred two thousand, six hundred forty".