261578099340 has 144 divisors (see below), whose sum is σ = 869097509280. Its totient is φ = 63387125760.

The previous prime is 261578099329. The next prime is 261578099351. The reversal of 261578099340 is 43990875162.

261578099340 is a `hidden beast` number, since 2 + 61 + 578 + 0 + 9 + 9 + 3 + 4 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (261578099329) and next prime (261578099351).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1385106 + ... + 1562585.

It is an arithmetic number, because the mean of its divisors is an integer number (6035399370).

It is a 1-persistent number, because it is pandigital, but 2⋅261578099340 = 523156198680 is not.

Almost surely, 2^261578099340 is an apocalyptic number.

261578099340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261578099340 is an abundant number, since it is smaller than the sum of its proper divisors (607519409940).

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

261578099340 is a wasteful number, since it uses less digits than its factorization.

261578099340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2947752 (or 2947747 counting only the distinct ones).

The product of its (nonzero) digits is 3265920, while the sum is 54.

The spelling of 261578099340 in words is "two hundred sixty-one billion, five hundred seventy-eight million, ninety-nine thousand, three hundred forty".