720121671 has 20 divisors (see below), whose sum is σ = 1077770232. Its totient is φ = 479173968.

The previous prime is 720121667. The next prime is 720121681. The reversal of 720121671 is 176121027.

It is not a de Polignac number, because 720121671 - 2² = 720121667 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720121601) 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 19 ways as a sum of consecutive naturals, for example, 36181 + ... + 52433.

Almost surely, 2^720121671 is an apocalyptic number.

720121671 is a deficient number, since it is larger than the sum of its proper divisors (357648561).

720121671 is a wasteful number, since it uses less digits than its factorization.

720121671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16812 (or 16803 counting only the distinct ones).

The product of its (nonzero) digits is 1176, while the sum is 27.

The square root of 720121671 is about 26835.0828394473. The cubic root of 720121671 is about 896.3314332268.

Adding to 720121671 its reverse (176121027), we get a palindrome (896242698).

The spelling of 720121671 in words is "seven hundred twenty million, one hundred twenty-one thousand, six hundred seventy-one".