261516021 has 8 divisors (see below), whose sum is σ = 375510240. Its totient is φ = 160932912.

The previous prime is 261516011. The next prime is 261516029. The reversal of 261516021 is 120615162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 261516021 - 2⁷ = 261515893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261515982 and 261516000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261516029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3352731 + ... + 3352808.

It is an arithmetic number, because the mean of its divisors is an integer number (46938780).

Almost surely, 2^261516021 is an apocalyptic number.

It is an amenable number.

261516021 is a deficient number, since it is larger than the sum of its proper divisors (113994219).

261516021 is a wasteful number, since it uses less digits than its factorization.

261516021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6705555.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 261516021 is about 16171.4569844526. The cubic root of 261516021 is about 639.4885407551.

The spelling of 261516021 in words is "two hundred sixty-one million, five hundred sixteen thousand, twenty-one".