21254645450 has 24 divisors (see below), whose sum is σ = 41614360320. Its totient is φ = 8054391600.

The previous prime is 21254645411. The next prime is 21254645473. The reversal of 21254645450 is 5454645212.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11185706 + ... + 11187605.

It is an arithmetic number, because the mean of its divisors is an integer number (1733931680).

Almost surely, 2^21254645450 is an apocalyptic number.

21254645450 is a deficient number, since it is larger than the sum of its proper divisors (20359714870).

21254645450 is a wasteful number, since it uses less digits than its factorization.

21254645450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22373342 (or 22373337 counting only the distinct ones).

The product of its (nonzero) digits is 192000, while the sum is 38.

The spelling of 21254645450 in words is "twenty-one billion, two hundred fifty-four million, six hundred forty-five thousand, four hundred fifty".