20121894428 has 6 divisors (see below), whose sum is σ = 35213315256. Its totient is φ = 10060947212.

The previous prime is 20121894427. The next prime is 20121894431. The reversal of 20121894428 is 82449812102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121894427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2515236800 + ... + 2515236807.

It is an arithmetic number, because the mean of its divisors is an integer number (5868885876).

Almost surely, 2^20121894428 is an apocalyptic number.

It is an amenable number.

20121894428 is a deficient number, since it is larger than the sum of its proper divisors (15091420828).

20121894428 is a wasteful number, since it uses less digits than its factorization.

20121894428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5030473611 (or 5030473609 counting only the distinct ones).

The product of its (nonzero) digits is 73728, while the sum is 41.

The spelling of 20121894428 in words is "twenty billion, one hundred twenty-one million, eight hundred ninety-four thousand, four hundred twenty-eight".