7210991817 has 8 divisors (see below), whose sum is σ = 10682950880. Its totient is φ = 4807327860.

The previous prime is 7210991771. The next prime is 7210991833. The reversal of 7210991817 is 7181990127.

It is a happy number.

It is not a de Polignac number, because 7210991817 - 2²² = 7206797513 is a prime.

It is a super-2 number, since 2×7210991817² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7210991857) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 133536859 + ... + 133536912.

It is an arithmetic number, because the mean of its divisors is an integer number (1335368860).

Almost surely, 2^7210991817 is an apocalyptic number.

It is an amenable number.

7210991817 is a deficient number, since it is larger than the sum of its proper divisors (3471959063).

7210991817 is a wasteful number, since it uses less digits than its factorization.

7210991817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 267073780 (or 267073774 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 45.

The square root of 7210991817 is about 84917.5589439546. The cubic root of 7210991817 is about 1931.9609068707.

The spelling of 7210991817 in words is "seven billion, two hundred ten million, nine hundred ninety-one thousand, eight hundred seventeen".