261420081 has 16 divisors (see below), whose sum is σ = 380518656. Its totient is φ = 158668416.

The previous prime is 261420079. The next prime is 261420113. The reversal of 261420081 is 180024162.

It is not a de Polignac number, because 261420081 - 2¹ = 261420079 is a prime.

It is a super-2 number, since 2×261420081² = 136680917500093122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261420881) 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, 43065 + ... + 48758.

It is an arithmetic number, because the mean of its divisors is an integer number (23782416).

Almost surely, 2^261420081 is an apocalyptic number.

It is an amenable number.

261420081 is a deficient number, since it is larger than the sum of its proper divisors (119098575).

261420081 is a wasteful number, since it uses less digits than its factorization.

261420081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91912.

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 261420081 is about 16168.4903748000. The cubic root of 261420081 is about 639.4103300787.

The spelling of 261420081 in words is "two hundred sixty-one million, four hundred twenty thousand, eighty-one".