261240163643503 has 32 divisors (see below), whose sum is σ = 286149086714880. Its totient is φ = 236527160970240.

The previous prime is 261240163643471. The next prime is 261240163643519. The reversal of 261240163643503 is 305346361042162.

It is a cyclic number.

It is not a de Polignac number, because 261240163643503 - 2⁵ = 261240163643471 is a prime.

It is a super-2 number, since 2×261240163643503² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261240163643533) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4526824213 + ... + 4526881921.

It is an arithmetic number, because the mean of its divisors is an integer number (8942158959840).

Almost surely, 2^{261240163643503} is an apocalyptic number.

261240163643503 is a deficient number, since it is larger than the sum of its proper divisors (24908923071377).

261240163643503 is a wasteful number, since it uses less digits than its factorization.

261240163643503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59959.

The product of its (nonzero) digits is 1866240, while the sum is 46.

The spelling of 261240163643503 in words is "two hundred sixty-one trillion, two hundred forty billion, one hundred sixty-three million, six hundred forty-three thousand, five hundred three".