71220631 has 4 divisors (see below), whose sum is σ = 71242264. Its totient is φ = 71199000.

The previous prime is 71220619. The next prime is 71220637. The reversal of 71220631 is 13602217.

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

It is a cyclic number.

It is not a de Polignac number, because 71220631 - 2⁷ = 71220503 is a prime.

It is a super-2 number, since 2×71220631² = 10144756560076322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71220637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4740 + ... + 12841.

It is an arithmetic number, because the mean of its divisors is an integer number (17810566).

Almost surely, 2^71220631 is an apocalyptic number.

71220631 is a deficient number, since it is larger than the sum of its proper divisors (21633).

71220631 is a wasteful number, since it uses less digits than its factorization.

71220631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21632.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 71220631 is about 8439.2316593396. The cubic root of 71220631 is about 414.5102482136.

Adding to 71220631 its reverse (13602217), we get a palindrome (84822848).

The spelling of 71220631 in words is "seventy-one million, two hundred twenty thousand, six hundred thirty-one".