261416540154625 has 16 divisors (see below), whose sum is σ = 327086525572560. Its totient is φ = 208595614521600.

The previous prime is 261416540154613. The next prime is 261416540154691. The reversal of 261416540154625 is 526451045614162.

It can be written as a sum of positive squares in 8 ways, for example, as 151015981788736 + 110400558365889 = 12288856^2 + 10507167^2 .

It is a de Polignac number, because none of the positive numbers 2^k-261416540154625 is a prime.

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, 2688039192 + ... + 2688136441.

It is an arithmetic number, because the mean of its divisors is an integer number (20442907848285).

Almost surely, 2^{261416540154625} is an apocalyptic number.

261416540154625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261416540154625 is a deficient number, since it is larger than the sum of its proper divisors (65669985417935).

261416540154625 is an equidigital number, since it uses as much as digits as its factorization.

261416540154625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5376176037 (or 5376176027 counting only the distinct ones).

The product of its (nonzero) digits is 6912000, while the sum is 52.

Adding to 261416540154625 its reverse (526451045614162), we get a palindrome (787867585768787).

The spelling of 261416540154625 in words is "two hundred sixty-one trillion, four hundred sixteen billion, five hundred forty million, one hundred fifty-four thousand, six hundred twenty-five".