21121022004157 has 2 divisors, whose sum is σ = 21121022004158. Its totient is φ = 21121022004156.

The previous prime is 21121022004107. The next prime is 21121022004169. The reversal of 21121022004157 is 75140022012112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18916358298436 + 2204663705721 = 4349294^2 + 1484811^2 .

It is a cyclic number.

It is not a de Polignac number, because 21121022004157 - 2²⁷ = 21120887786429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21121022004107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560511002078 + 10560511002079.

It is an arithmetic number, because the mean of its divisors is an integer number (10560511002079).

Almost surely, 2^{21121022004157} is an apocalyptic number.

It is an amenable number.

21121022004157 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121022004157 is an equidigital number, since it uses as much as digits as its factorization.

21121022004157 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2240, while the sum is 28.

Adding to 21121022004157 its reverse (75140022012112), we get a palindrome (96261044016269).

The spelling of 21121022004157 in words is "twenty-one trillion, one hundred twenty-one billion, twenty-two million, four thousand, one hundred fifty-seven".