71261987 has 4 divisors (see below), whose sum is σ = 71674080. Its totient is φ = 70849896.

The previous prime is 71261959. The next prime is 71261999. The reversal of 71261987 is 78916217.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78916217 = 59 ⋅1337563.

It is a cyclic number.

It is not a de Polignac number, because 71261987 - 2¹² = 71257891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71261087) 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, 205787 + ... + 206132.

It is an arithmetic number, because the mean of its divisors is an integer number (17918520).

Almost surely, 2^71261987 is an apocalyptic number.

71261987 is a deficient number, since it is larger than the sum of its proper divisors (412093).

71261987 is a wasteful number, since it uses less digits than its factorization.

71261987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412092.

The product of its digits is 42336, while the sum is 41.

The square root of 71261987 is about 8441.6815268050. The cubic root of 71261987 is about 414.5904645244.

The spelling of 71261987 in words is "seventy-one million, two hundred sixty-one thousand, nine hundred eighty-seven".