71152021 has 4 divisors (see below), whose sum is σ = 75337452. Its totient is φ = 66966592.

The previous prime is 71152019. The next prime is 71152027. The reversal of 71152021 is 12025117.

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 52403121 + 18748900 = 7239^2 + 4330^2 .

It is a cyclic number.

It is not a de Polignac number, because 71152021 - 2¹ = 71152019 is a prime.

It is a super-2 number, since 2×71152021² = 10125220184768882, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71152021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71152027) 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, 2092690 + ... + 2092723.

It is an arithmetic number, because the mean of its divisors is an integer number (18834363).

Almost surely, 2^71152021 is an apocalyptic number.

It is an amenable number.

71152021 is a deficient number, since it is larger than the sum of its proper divisors (4185431).

71152021 is a wasteful number, since it uses less digits than its factorization.

71152021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4185430.

The product of its (nonzero) digits is 140, while the sum is 19.

The square root of 71152021 is about 8435.1657363682. The cubic root of 71152021 is about 414.3771000654.

Adding to 71152021 its reverse (12025117), we get a palindrome (83177138).

The spelling of 71152021 in words is "seventy-one million, one hundred fifty-two thousand, twenty-one".