21551402452305 has 64 divisors (see below), whose sum is σ = 39597794887680. Its totient is φ = 9898968844800.

The previous prime is 21551402452259. The next prime is 21551402452379. The reversal of 21551402452305 is 50325420415512.

It is not a de Polignac number, because 21551402452305 - 2¹⁰ = 21551402451281 is a prime.

It is a super-2 number, since 2×21551402452305² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 235584004 + ... + 235675466.

It is an arithmetic number, because the mean of its divisors is an integer number (618715545120).

Almost surely, 2^{21551402452305} is an apocalyptic number.

It is an amenable number.

21551402452305 is a deficient number, since it is larger than the sum of its proper divisors (18046392435375).

21551402452305 is a wasteful number, since it uses less digits than its factorization.

21551402452305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166662.

The product of its (nonzero) digits is 240000, while the sum is 39.

Adding to 21551402452305 its reverse (50325420415512), we get a palindrome (71876822867817).

The spelling of 21551402452305 in words is "twenty-one trillion, five hundred fifty-one billion, four hundred two million, four hundred fifty-two thousand, three hundred five".