20421100020149 has 2 divisors, whose sum is σ = 20421100020150. Its totient is φ = 20421100020148.

The previous prime is 20421100020017. The next prime is 20421100020193. The reversal of 20421100020149 is 94102000112402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18443743765924 + 1977356254225 = 4294618^2 + 1406185^2 .

It is a cyclic number.

It is not a de Polignac number, because 20421100020149 - 2¹⁶ = 20421099954613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20421100040149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10210550010074 + 10210550010075.

It is an arithmetic number, because the mean of its divisors is an integer number (10210550010075).

Almost surely, 2^{20421100020149} is an apocalyptic number.

It is an amenable number.

20421100020149 is a deficient number, since it is larger than the sum of its proper divisors (1).

20421100020149 is an equidigital number, since it uses as much as digits as its factorization.

20421100020149 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 26.

The spelling of 20421100020149 in words is "twenty trillion, four hundred twenty-one billion, one hundred million, twenty thousand, one hundred forty-nine".