21120975804493 has 2 divisors, whose sum is σ = 21120975804494. Its totient is φ = 21120975804492.

The previous prime is 21120975804469. The next prime is 21120975804521. The reversal of 21120975804493 is 39440857902112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19580244451849 + 1540731352644 = 4424957^2 + 1241262^2 .

It is a cyclic number.

It is not a de Polignac number, because 21120975804493 - 2¹³ = 21120975796301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21120975801493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560487902246 + 10560487902247.

It is an arithmetic number, because the mean of its divisors is an integer number (10560487902247).

Almost surely, 2^{21120975804493} is an apocalyptic number.

It is an amenable number.

21120975804493 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120975804493 is an equidigital number, since it uses as much as digits as its factorization.

21120975804493 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4354560, while the sum is 55.

The spelling of 21120975804493 in words is "twenty-one trillion, one hundred twenty billion, nine hundred seventy-five million, eight hundred four thousand, four hundred ninety-three".