71497021 has 4 divisors (see below), whose sum is σ = 72129852. Its totient is φ = 70864192.

The previous prime is 71497009. The next prime is 71497031. The reversal of 71497021 is 12079417.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7672900 + 63824121 = 2770^2 + 7989^2 .

It is a cyclic number.

It is not a de Polignac number, because 71497021 - 2²³ = 63108413 is a prime.

It is a super-2 number, since 2×71497021² = 10223648023748882, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71497031) 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, 316246 + ... + 316471.

It is an arithmetic number, because the mean of its divisors is an integer number (18032463).

Almost surely, 2^71497021 is an apocalyptic number.

It is an amenable number.

71497021 is a deficient number, since it is larger than the sum of its proper divisors (632831).

71497021 is a wasteful number, since it uses less digits than its factorization.

71497021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 632830.

The product of its (nonzero) digits is 3528, while the sum is 31.

The square root of 71497021 is about 8455.5911088463. The cubic root of 71497021 is about 415.0457606674.

The spelling of 71497021 in words is "seventy-one million, four hundred ninety-seven thousand, twenty-one".