261416421 has 48 divisors (see below), whose sum is σ = 463632000. Its totient is φ = 141486912.

The previous prime is 261416417. The next prime is 261416443. The reversal of 261416421 is 124614162.

261416421 is a `hidden beast` number, since 2 + 6 + 14 + 1 + 642 + 1 = 666.

It is not a de Polignac number, because 261416421 - 2² = 261416417 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261416401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 56425 + ... + 60881.

It is an arithmetic number, because the mean of its divisors is an integer number (9659000).

Almost surely, 2^261416421 is an apocalyptic number.

261416421 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

261416421 is a deficient number, since it is larger than the sum of its proper divisors (202215579).

261416421 is a wasteful number, since it uses less digits than its factorization.

261416421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4503 (or 4486 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 261416421 is about 16168.3771912954. The cubic root of 261416421 is about 639.4073460529.

The spelling of 261416421 in words is "two hundred sixty-one million, four hundred sixteen thousand, four hundred twenty-one".