261066421 has 16 divisors (see below), whose sum is σ = 325946880. Its totient is φ = 203140080.

The previous prime is 261066419. The next prime is 261066431. The reversal of 261066421 is 124660162.

It is not a de Polignac number, because 261066421 - 2¹ = 261066419 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261066421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261066401) 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, 64170 + ... + 68116.

It is an arithmetic number, because the mean of its divisors is an integer number (20371680).

Almost surely, 2^261066421 is an apocalyptic number.

It is an amenable number.

261066421 is a deficient number, since it is larger than the sum of its proper divisors (64880459).

261066421 is a wasteful number, since it uses less digits than its factorization.

261066421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4824.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 261066421 is about 16157.5499689774. The cubic root of 261066421 is about 639.1218596245.

The spelling of 261066421 in words is "two hundred sixty-one million, sixty-six thousand, four hundred twenty-one".