71291621 has 4 divisors (see below), whose sum is σ = 72808512. Its totient is φ = 69774732.

The previous prime is 71291609. The next prime is 71291653. The reversal of 71291621 is 12619217.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 71291621 - 2¹⁸ = 71029477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71291681) 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, 758375 + ... + 758468.

It is an arithmetic number, because the mean of its divisors is an integer number (18202128).

Almost surely, 2^71291621 is an apocalyptic number.

It is an amenable number.

71291621 is a deficient number, since it is larger than the sum of its proper divisors (1516891).

71291621 is a wasteful number, since it uses less digits than its factorization.

71291621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1516890.

The product of its digits is 1512, while the sum is 29.

The square root of 71291621 is about 8443.4365633905. The cubic root of 71291621 is about 414.6479251319.

The spelling of 71291621 in words is "seventy-one million, two hundred ninety-one thousand, six hundred twenty-one".