16020721237 has 2 divisors, whose sum is σ = 16020721238. Its totient is φ = 16020721236.

The previous prime is 16020721219. The next prime is 16020721247. The reversal of 16020721237 is 73212702061.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11713949361 + 4306771876 = 108231^2 + 65626^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16020721237 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16020721199 and 16020721208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16020721247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8010360618 + 8010360619.

It is an arithmetic number, because the mean of its divisors is an integer number (8010360619).

Almost surely, 2^16020721237 is an apocalyptic number.

It is an amenable number.

16020721237 is a deficient number, since it is larger than the sum of its proper divisors (1).

16020721237 is an equidigital number, since it uses as much as digits as its factorization.

16020721237 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7056, while the sum is 31.

The spelling of 16020721237 in words is "sixteen billion, twenty million, seven hundred twenty-one thousand, two hundred thirty-seven".