20545201640 has 128 divisors (see below), whose sum is σ = 49156070400. Its totient is φ = 7714621440.

The previous prime is 20545201637. The next prime is 20545201669. The reversal of 20545201640 is 4610254502.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26105327 + ... + 26106113.

It is an arithmetic number, because the mean of its divisors is an integer number (384031800).

Almost surely, 2^20545201640 is an apocalyptic number.

20545201640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20545201640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24578035200).

20545201640 is an abundant number, since it is smaller than the sum of its proper divisors (28610868760).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20545201640 is a wasteful number, since it uses less digits than its factorization.

20545201640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1435 (or 1431 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 29.

The spelling of 20545201640 in words is "twenty billion, five hundred forty-five million, two hundred one thousand, six hundred forty".