21155354055 has 48 divisors (see below), whose sum is σ = 40017144960. Its totient is φ = 10253476800.

The previous prime is 21155354009. The next prime is 21155354071. The reversal of 21155354055 is 55045355112.

21155354055 is a `hidden beast` number, since 2 + 1 + 1 + 553 + 54 + 0 + 55 = 666.

It is not a de Polignac number, because 21155354055 - 2¹⁷ = 21155222983 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1821256 + ... + 1832834.

It is an arithmetic number, because the mean of its divisors is an integer number (833690520).

Almost surely, 2^21155354055 is an apocalyptic number.

21155354055 is a deficient number, since it is larger than the sum of its proper divisors (18861790905).

21155354055 is a wasteful number, since it uses less digits than its factorization.

21155354055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15292 (or 15289 counting only the distinct ones).

The product of its (nonzero) digits is 75000, while the sum is 36.

The spelling of 21155354055 in words is "twenty-one billion, one hundred fifty-five million, three hundred fifty-four thousand, fifty-five".