20128557494 has 8 divisors (see below), whose sum is σ = 30504102888. Its totient is φ = 9960523200.

The previous prime is 20128557487. The next prime is 20128557511. The reversal of 20128557494 is 49475582102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51877532 + ... + 51877919.

It is an arithmetic number, because the mean of its divisors is an integer number (3813012861).

Almost surely, 2^20128557494 is an apocalyptic number.

20128557494 is a deficient number, since it is larger than the sum of its proper divisors (10375545394).

20128557494 is a wasteful number, since it uses less digits than its factorization.

20128557494 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103755550.

The product of its (nonzero) digits is 806400, while the sum is 47.

The spelling of 20128557494 in words is "twenty billion, one hundred twenty-eight million, five hundred fifty-seven thousand, four hundred ninety-four".