21255125055 has 8 divisors (see below), whose sum is σ = 34008200112. Its totient is φ = 11336066688.

The previous prime is 21255125039. The next prime is 21255125069. The reversal of 21255125055 is 55052155212.

It is a happy number.

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

It is not a de Polignac number, because 21255125055 - 2⁴ = 21255125039 is a prime.

It is a super-2 number, since 2×21255125055² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

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, 708504154 + ... + 708504183.

It is an arithmetic number, because the mean of its divisors is an integer number (4251025014).

Almost surely, 2^21255125055 is an apocalyptic number.

21255125055 is a deficient number, since it is larger than the sum of its proper divisors (12753075057).

21255125055 is a wasteful number, since it uses less digits than its factorization.

21255125055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1417008345.

The product of its (nonzero) digits is 25000, while the sum is 33.

The spelling of 21255125055 in words is "twenty-one billion, two hundred fifty-five million, one hundred twenty-five thousand, fifty-five".