71187220 has 24 divisors (see below), whose sum is σ = 160993224. Its totient is φ = 26284416.

The previous prime is 71187209. The next prime is 71187229. The reversal of 71187220 is 2278117.

It can be written as a sum of positive squares in 4 ways, for example, as 929296 + 70257924 = 964^2 + 8382^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71187229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 136639 + ... + 137158.

It is an arithmetic number, because the mean of its divisors is an integer number (6708051).

Almost surely, 2^71187220 is an apocalyptic number.

It is an amenable number.

71187220 is an abundant number, since it is smaller than the sum of its proper divisors (89806004).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

71187220 is a wasteful number, since it uses less digits than its factorization.

71187220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273819 (or 273817 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 28.

The square root of 71187220 is about 8437.2519222790. The cubic root of 71187220 is about 414.4454197693.

The spelling of 71187220 in words is "seventy-one million, one hundred eighty-seven thousand, two hundred twenty".