20645401408 has 28 divisors (see below), whose sum is σ = 41461822080. Its totient is φ = 10198328192.

The previous prime is 20645401379. The next prime is 20645401417. The reversal of 20645401408 is 80410454602.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 1937968 + ... + 1948591.

It is an arithmetic number, because the mean of its divisors is an integer number (1480779360).

Almost surely, 2^20645401408 is an apocalyptic number.

It is an amenable number.

20645401408 is an abundant number, since it is smaller than the sum of its proper divisors (20816420672).

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

20645401408 is an equidigital number, since it uses as much as digits as its factorization.

20645401408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3886654 (or 3886644 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 34.

The spelling of 20645401408 in words is "twenty billion, six hundred forty-five million, four hundred one thousand, four hundred eight".