71290640 has 20 divisors (see below), whose sum is σ = 165750924. Its totient is φ = 28516224.

The previous prime is 71290577. The next prime is 71290657. The reversal of 71290640 is 4609217.

It can be written as a sum of positive squares in 2 ways, for example, as 43454464 + 27836176 = 6592^2 + 5276^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 445487 + ... + 445646.

Almost surely, 2^71290640 is an apocalyptic number.

It is an amenable number.

71290640 is an abundant number, since it is smaller than the sum of its proper divisors (94460284).

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

71290640 is a wasteful number, since it uses less digits than its factorization.

71290640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 891146 (or 891140 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 71290640 is about 8443.3784707308. The cubic root of 71290640 is about 414.6460232185.

Adding to 71290640 its reverse (4609217), we get a palindrome (75899857).

The spelling of 71290640 in words is "seventy-one million, two hundred ninety thousand, six hundred forty".