21404204155 has 8 divisors (see below), whose sum is σ = 25687386000. Its totient is φ = 17121802656.

The previous prime is 21404204149. The next prime is 21404204189. The reversal of 21404204155 is 55140240412.

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 21404204155 - 2⁷ = 21404204027 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 132940 + ... + 245929.

It is an arithmetic number, because the mean of its divisors is an integer number (3210923250).

Almost surely, 2^21404204155 is an apocalyptic number.

21404204155 is a deficient number, since it is larger than the sum of its proper divisors (4283181845).

21404204155 is a wasteful number, since it uses less digits than its factorization.

21404204155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 390173.

The product of its (nonzero) digits is 6400, while the sum is 28.

Adding to 21404204155 its reverse (55140240412), we get a palindrome (76544444567).

The spelling of 21404204155 in words is "twenty-one billion, four hundred four million, two hundred four thousand, one hundred fifty-five".