21401355041551 has 8 divisors (see below), whose sum is σ = 21979828312064. Its totient is φ = 20822884837920.

The previous prime is 21401355041533. The next prime is 21401355041609. The reversal of 21401355041551 is 15514055310412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21401355041551 - 2⁵ = 21401355041519 is a prime.

It is a super-2 number, since 2×21401355041551² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21401355041551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21401355041351) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24345586 + ... + 25209328.

It is an arithmetic number, because the mean of its divisors is an integer number (2747478539008).

Almost surely, 2^{21401355041551} is an apocalyptic number.

21401355041551 is a deficient number, since it is larger than the sum of its proper divisors (578473270513).

21401355041551 is an equidigital number, since it uses as much as digits as its factorization.

21401355041551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1533441.

The product of its (nonzero) digits is 60000, while the sum is 37.

The spelling of 21401355041551 in words is "twenty-one trillion, four hundred one billion, three hundred fifty-five million, forty-one thousand, five hundred fifty-one".