21428499457 has 8 divisors (see below), whose sum is σ = 21469081536. Its totient is φ = 21387945072.

The previous prime is 21428499451. The next prime is 21428499467. The reversal of 21428499457 is 75499482412.

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 21428499457 - 2⁷ = 21428499329 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21428499398 and 21428499407.

It is not an unprimeable number, because it can be changed into a prime (21428499451) 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, 2136348 + ... + 2146354.

It is an arithmetic number, because the mean of its divisors is an integer number (2683635192).

Almost surely, 2^21428499457 is an apocalyptic number.

It is an amenable number.

21428499457 is a deficient number, since it is larger than the sum of its proper divisors (40582079).

21428499457 is a wasteful number, since it uses less digits than its factorization.

21428499457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13847.

The product of its digits is 5806080, while the sum is 55.

The spelling of 21428499457 in words is "twenty-one billion, four hundred twenty-eight million, four hundred ninety-nine thousand, four hundred fifty-seven".