21054663623 has 8 divisors (see below), whose sum is σ = 24067419648. Its totient is φ = 18043144344.

The previous prime is 21054663587. The next prime is 21054663671. The reversal of 21054663623 is 32636645012.

It is a happy number.

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 21054663623 - 2²⁶ = 20987554759 is a prime.

It is a super-2 number, since 2×21054663623² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21054663023) 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, 272411 + ... + 341052.

It is an arithmetic number, because the mean of its divisors is an integer number (3008427456).

Almost surely, 2^21054663623 is an apocalyptic number.

21054663623 is a deficient number, since it is larger than the sum of its proper divisors (3012756025).

21054663623 is an equidigital number, since it uses as much as digits as its factorization.

21054663623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 618373.

The product of its (nonzero) digits is 155520, while the sum is 38.

The spelling of 21054663623 in words is "twenty-one billion, fifty-four million, six hundred sixty-three thousand, six hundred twenty-three".