71297520 has 240 divisors, whose sum is σ = 267982848. Its totient is φ = 15344640.

The previous prime is 71297509. The next prime is 71297531. The reversal of 71297520 is 2579217.

It is an interprime number because it is at equal distance from previous prime (71297509) and next prime (71297531).

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1926942 + ... + 1926978.

Almost surely, 2^71297520 is an apocalyptic number.

71297520 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71297520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133991424).

71297520 is an abundant number, since it is smaller than the sum of its proper divisors (196685328).

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

71297520 is a wasteful number, since it uses less digits than its factorization.

71297520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128 (or 85 counting only the distinct ones).

The product of its (nonzero) digits is 8820, while the sum is 33.

The square root of 71297520 is about 8443.7858807528. The cubic root of 71297520 is about 414.6593614485.

It can be divided in two parts, 71297 and 520, that added together give a palindrome (71817).

The spelling of 71297520 in words is "seventy-one million, two hundred ninety-seven thousand, five hundred twenty".