21053505012403 has 2 divisors, whose sum is σ = 21053505012404. Its totient is φ = 21053505012402.

The previous prime is 21053505012367. The next prime is 21053505012409. The reversal of 21053505012403 is 30421050535012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21053505012403 - 2¹³ = 21053505004211 is a prime.

It is not a weakly prime, because it can be changed into another prime (21053505012409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10526752506201 + 10526752506202.

It is an arithmetic number, because the mean of its divisors is an integer number (10526752506202).

Almost surely, 2^{21053505012403} is an apocalyptic number.

21053505012403 is a deficient number, since it is larger than the sum of its proper divisors (1).

21053505012403 is an equidigital number, since it uses as much as digits as its factorization.

21053505012403 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18000, while the sum is 31.

Adding to 21053505012403 its reverse (30421050535012), we get a palindrome (51474555547415).

The spelling of 21053505012403 in words is "twenty-one trillion, fifty-three billion, five hundred five million, twelve thousand, four hundred three".