261518028 has 12 divisors (see below), whose sum is σ = 610208760. Its totient is φ = 87172672.

The previous prime is 261518003. The next prime is 261518053. The reversal of 261518028 is 820815162.

It is an interprime number because it is at equal distance from previous prime (261518003) and next prime (261518053).

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 261518028.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10896573 + ... + 10896596.

It is an arithmetic number, because the mean of its divisors is an integer number (50850730).

Almost surely, 2^261518028 is an apocalyptic number.

It is an amenable number.

261518028 is an abundant number, since it is smaller than the sum of its proper divisors (348690732).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261518028 is a wasteful number, since it uses less digits than its factorization.

261518028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21793176 (or 21793174 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 33.

The square root of 261518028 is about 16171.5190381114. The cubic root of 261518028 is about 639.4901766654.

The spelling of 261518028 in words is "two hundred sixty-one million, five hundred eighteen thousand, twenty-eight".