261504015 has 32 divisors (see below), whose sum is σ = 426408960. Its totient is φ = 136819584.

The previous prime is 261503993. The next prime is 261504029. The reversal of 261504015 is 510405162.

It is not a de Polignac number, because 261504015 - 2¹⁰ = 261502991 is a prime.

It is a super-2 number, since 2×261504015² = 136768699722240450, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 368481 + ... + 369189.

It is an arithmetic number, because the mean of its divisors is an integer number (13325280).

Almost surely, 2^261504015 is an apocalyptic number.

261504015 is a deficient number, since it is larger than the sum of its proper divisors (164904945).

261504015 is a wasteful number, since it uses less digits than its factorization.

261504015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1151.

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 261504015 is about 16171.0857705969. The cubic root of 261504015 is about 639.4787544625.

Adding to 261504015 its reverse (510405162), we get a palindrome (771909177).

The spelling of 261504015 in words is "two hundred sixty-one million, five hundred four thousand, fifteen".