21247180478 has 16 divisors (see below), whose sum is σ = 32135904144. Its totient is φ = 10535577600.

The previous prime is 21247180459. The next prime is 21247180517. The reversal of 21247180478 is 87408174212.

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, 25628 + ... + 207728.

It is an arithmetic number, because the mean of its divisors is an integer number (2008494009).

Almost surely, 2^21247180478 is an apocalyptic number.

21247180478 is a deficient number, since it is larger than the sum of its proper divisors (10888723666).

21247180478 is a wasteful number, since it uses less digits than its factorization.

21247180478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182587.

The product of its (nonzero) digits is 200704, while the sum is 44.

The spelling of 21247180478 in words is "twenty-one billion, two hundred forty-seven million, one hundred eighty thousand, four hundred seventy-eight".