21254684477 has 8 divisors (see below), whose sum is σ = 23103583776. Its totient is φ = 19436345712.

The previous prime is 21254684459. The next prime is 21254684483. The reversal of 21254684477 is 77448645212.

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 21254684477 - 2⁸ = 21254684221 is a prime.

It is a super-2 number, since 2×21254684477² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21254684497) 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, 7638683 + ... + 7641464.

It is an arithmetic number, because the mean of its divisors is an integer number (2887947972).

Almost surely, 2^21254684477 is an apocalyptic number.

It is an amenable number.

21254684477 is a deficient number, since it is larger than the sum of its proper divisors (1848899299).

21254684477 is a wasteful number, since it uses less digits than its factorization.

21254684477 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15280267.

The product of its digits is 3010560, while the sum is 50.

The spelling of 21254684477 in words is "twenty-one billion, two hundred fifty-four million, six hundred eighty-four thousand, four hundred seventy-seven".