16220763721 has 8 divisors (see below), whose sum is σ = 16421459400. Its totient is φ = 16020854400.

The previous prime is 16220763697. The next prime is 16220763763. The reversal of 16220763721 is 12736702261.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 13055576121 + 3165187600 = 114261^2 + 56260^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16220763721 - 2¹⁹ = 16220239433 is a prime.

It is a super-2 number, since 2×16220763721² (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 (16220763781) 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, 155026 + ... + 237643.

It is an arithmetic number, because the mean of its divisors is an integer number (2052682425).

Almost surely, 2^16220763721 is an apocalyptic number.

It is an amenable number.

16220763721 is a deficient number, since it is larger than the sum of its proper divisors (200695679).

16220763721 is a wasteful number, since it uses less digits than its factorization.

16220763721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393179.

The product of its (nonzero) digits is 42336, while the sum is 37.

The spelling of 16220763721 in words is "sixteen billion, two hundred twenty million, seven hundred sixty-three thousand, seven hundred twenty-one".