261420671 has 4 divisors (see below), whose sum is σ = 261482712. Its totient is φ = 261358632.

The previous prime is 261420661. The next prime is 261420683. The reversal of 261420671 is 176024162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 261420671 - 2²² = 257226367 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261420661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24200 + ... + 33293.

It is an arithmetic number, because the mean of its divisors is an integer number (65370678).

Almost surely, 2^261420671 is an apocalyptic number.

261420671 is a deficient number, since it is larger than the sum of its proper divisors (62041).

261420671 is an equidigital number, since it uses as much as digits as its factorization.

261420671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62040.

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 261420671 is about 16168.5086201542. The cubic root of 261420671 is about 639.4108111075.

The spelling of 261420671 in words is "two hundred sixty-one million, four hundred twenty thousand, six hundred seventy-one".