16520211153961 has 2 divisors, whose sum is σ = 16520211153962. Its totient is φ = 16520211153960.

The previous prime is 16520211153923. The next prime is 16520211153997. The reversal of 16520211153961 is 16935111202561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12108005878336 + 4412205275625 = 3479656^2 + 2100525^2 .

It is an emirp because it is prime and its reverse (16935111202561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16520211153961 - 2⁹ = 16520211153449 is a prime.

It is not a weakly prime, because it can be changed into another prime (16520211153911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8260105576980 + 8260105576981.

It is an arithmetic number, because the mean of its divisors is an integer number (8260105576981).

Almost surely, 2^{16520211153961} is an apocalyptic number.

It is an amenable number.

16520211153961 is a deficient number, since it is larger than the sum of its proper divisors (1).

16520211153961 is an equidigital number, since it uses as much as digits as its factorization.

16520211153961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 97200, while the sum is 43.

The spelling of 16520211153961 in words is "sixteen trillion, five hundred twenty billion, two hundred eleven million, one hundred fifty-three thousand, nine hundred sixty-one".