20900581640929 has 4 divisors (see below), whose sum is σ = 20900597629360. Its totient is φ = 20900565652500.

The previous prime is 20900581640881. The next prime is 20900581641029. The reversal of 20900581640929 is 92904618500902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20900581640929 - 2⁷ = 20900581640801 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20900581640929.

It is not an unprimeable number, because it can be changed into a prime (20900581646929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5839839 + ... + 8712340.

It is an arithmetic number, because the mean of its divisors is an integer number (5225149407340).

Almost surely, 2^{20900581640929} is an apocalyptic number.

It is an amenable number.

20900581640929 is a deficient number, since it is larger than the sum of its proper divisors (15988431).

20900581640929 is a wasteful number, since it uses less digits than its factorization.

20900581640929 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15988430.

The product of its (nonzero) digits is 2799360, while the sum is 55.

The spelling of 20900581640929 in words is "twenty trillion, nine hundred billion, five hundred eighty-one million, six hundred forty thousand, nine hundred twenty-nine".