21221783311513 has 2 divisors, whose sum is σ = 21221783311514. Its totient is φ = 21221783311512.

The previous prime is 21221783311409. The next prime is 21221783311517. The reversal of 21221783311513 is 31511338712212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11691769778329 + 9530013533184 = 3419323^2 + 3087072^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221783311513 - 2¹⁷ = 21221783180441 is a prime.

It is not a weakly prime, because it can be changed into another prime (21221783311517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610891655756 + 10610891655757.

It is an arithmetic number, because the mean of its divisors is an integer number (10610891655757).

Almost surely, 2^{21221783311513} is an apocalyptic number.

It is an amenable number.

21221783311513 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221783311513 is an equidigital number, since it uses as much as digits as its factorization.

21221783311513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 40.

The spelling of 21221783311513 in words is "twenty-one trillion, two hundred twenty-one billion, seven hundred eighty-three million, three hundred eleven thousand, five hundred thirteen".