71905561 has 8 divisors (see below), whose sum is σ = 88499264. Its totient is φ = 56892240.

The previous prime is 71905549. The next prime is 71905571. The reversal of 71905561 is 16550917.

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

It is a cyclic number.

It is not a de Polignac number, because 71905561 - 2⁹ = 71905049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (71905571) 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, 394995 + ... + 395176.

It is an arithmetic number, because the mean of its divisors is an integer number (11062408).

Almost surely, 2^71905561 is an apocalyptic number.

It is an amenable number.

71905561 is a deficient number, since it is larger than the sum of its proper divisors (16593703).

71905561 is a wasteful number, since it uses less digits than its factorization.

71905561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 790191.

The product of its (nonzero) digits is 9450, while the sum is 34.

The square root of 71905561 is about 8479.7146768037. The cubic root of 71905561 is about 415.8347951786.

The spelling of 71905561 in words is "seventy-one million, nine hundred five thousand, five hundred sixty-one".