21551411611 has 8 divisors (see below), whose sum is σ = 21619437840. Its totient is φ = 21483479808.

The previous prime is 21551411603. The next prime is 21551411647. The reversal of 21551411611 is 11611415512.

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 21551411611 - 2³ = 21551411603 is a prime.

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 21551411611.

It is not an unprimeable number, because it can be changed into a prime (21551411311) 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, 448335 + ... + 494071.

It is an arithmetic number, because the mean of its divisors is an integer number (2702429730).

Almost surely, 2^21551411611 is an apocalyptic number.

21551411611 is a deficient number, since it is larger than the sum of its proper divisors (68026229).

21551411611 is a wasteful number, since it uses less digits than its factorization.

21551411611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47213.

The product of its digits is 1200, while the sum is 28.

The spelling of 21551411611 in words is "twenty-one billion, five hundred fifty-one million, four hundred eleven thousand, six hundred eleven".