261790305649 has 8 divisors (see below), whose sum is σ = 267918723072. Its totient is φ = 255663718800.

The previous prime is 261790305611. The next prime is 261790305677. The reversal of 261790305649 is 946503097162.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261790305649 - 2²³ = 261781917041 is a prime.

It is a super-2 number, since 2×261790305649² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261790305596 and 261790305605.

It is not an unprimeable number, because it can be changed into a prime (261790300649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 166129 + ... + 742414.

It is an arithmetic number, because the mean of its divisors is an integer number (33489840384).

Almost surely, 2^261790305649 is an apocalyptic number.

It is an amenable number.

261790305649 is a deficient number, since it is larger than the sum of its proper divisors (6128417423).

261790305649 is an equidigital number, since it uses as much as digits as its factorization.

261790305649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 915287.

The product of its (nonzero) digits is 2449440, while the sum is 52.

The spelling of 261790305649 in words is "two hundred sixty-one billion, seven hundred ninety million, three hundred five thousand, six hundred forty-nine".