71020640 has 24 divisors (see below), whose sum is σ = 167786640. Its totient is φ = 28408192.

The previous prime is 71020637. The next prime is 71020643. The reversal of 71020640 is 4602017.

It is an interprime number because it is at equal distance from previous prime (71020637) and next prime (71020643).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71020643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 221780 + ... + 222099.

It is an arithmetic number, because the mean of its divisors is an integer number (6991110).

Almost surely, 2^71020640 is an apocalyptic number.

It is an amenable number.

71020640 is an abundant number, since it is smaller than the sum of its proper divisors (96766000).

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

71020640 is a wasteful number, since it uses less digits than its factorization.

71020640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 443894 (or 443886 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 71020640 is about 8427.3744428499. The cubic root of 71020640 is about 414.1218961619.

Adding to 71020640 its reverse (4602017), we get a palindrome (75622657).

The spelling of 71020640 in words is "seventy-one million, twenty thousand, six hundred forty".