261226540 has 48 divisors (see below), whose sum is σ = 557863488. Its totient is φ = 102737664.

The previous prime is 261226523. The next prime is 261226541. The reversal of 261226540 is 45622162.

It is a junction number, because it is equal to n+sod(n) for n = 261226499 and 261226508.

It is not an unprimeable number, because it can be changed into a prime (261226541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 356014 + ... + 356746.

It is an arithmetic number, because the mean of its divisors is an integer number (11622156).

Almost surely, 2^261226540 is an apocalyptic number.

261226540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261226540 is an abundant number, since it is smaller than the sum of its proper divisors (296636948).

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

261226540 is a wasteful number, since it uses less digits than its factorization.

261226540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1018 (or 1016 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 261226540 is about 16162.5041376638. The cubic root of 261226540 is about 639.2524964155.

It can be divided in two parts, 261 and 226540, that added together give a triangular number (226801 = T₆₇₃).

The spelling of 261226540 in words is "two hundred sixty-one million, two hundred twenty-six thousand, five hundred forty".