21404301115551 has 16 divisors (see below), whose sum is σ = 29147052676608. Its totient is φ = 13965557864000.

The previous prime is 21404301115469. The next prime is 21404301115619. The reversal of 21404301115551 is 15551110340412.

It is a cyclic number.

It is not a de Polignac number, because 21404301115551 - 2⁷ = 21404301115423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21404301115151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3399436 + ... + 7373246.

It is an arithmetic number, because the mean of its divisors is an integer number (1821690792288).

Almost surely, 2^{21404301115551} is an apocalyptic number.

21404301115551 is a deficient number, since it is larger than the sum of its proper divisors (7742751561057).

21404301115551 is a wasteful number, since it uses less digits than its factorization.

21404301115551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4012062.

The product of its (nonzero) digits is 12000, while the sum is 33.

Adding to 21404301115551 its reverse (15551110340412), we get a palindrome (36955411455963).

The spelling of 21404301115551 in words is "twenty-one trillion, four hundred four billion, three hundred one million, one hundred fifteen thousand, five hundred fifty-one".