261520023 has 16 divisors (see below), whose sum is σ = 357458816. Its totient is φ = 169979040.

The previous prime is 261520019. The next prime is 261520031. The reversal of 261520023 is 320025162.

It is not a de Polignac number, because 261520023 - 2² = 261520019 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261520013) 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, 83736 + ... + 86802.

It is an arithmetic number, because the mean of its divisors is an integer number (22341176).

Almost surely, 2^261520023 is an apocalyptic number.

261520023 is a deficient number, since it is larger than the sum of its proper divisors (95938793).

261520023 is a wasteful number, since it uses less digits than its factorization.

261520023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3774.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 261520023 is about 16171.5807205109. The cubic root of 261520023 is about 639.4918027861.

Adding to 261520023 its reverse (320025162), we get a palindrome (581545185).

The spelling of 261520023 in words is "two hundred sixty-one million, five hundred twenty thousand, twenty-three".