20989050505 has 16 divisors (see below), whose sum is σ = 25432243200. Its totient is φ = 16628431680.

The previous prime is 20989050463. The next prime is 20989050571. The reversal of 20989050505 is 50505098902.

It is not a de Polignac number, because 20989050505 - 2⁷ = 20989050377 is a prime.

It is a super-2 number, since 2×20989050505² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 167776 + ... + 264814.

It is an arithmetic number, because the mean of its divisors is an integer number (1589515200).

Almost surely, 2^20989050505 is an apocalyptic number.

It is an amenable number.

20989050505 is a deficient number, since it is larger than the sum of its proper divisors (4443192695).

20989050505 is a wasteful number, since it uses less digits than its factorization.

20989050505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97464.

The product of its (nonzero) digits is 162000, while the sum is 43.

The spelling of 20989050505 in words is "twenty billion, nine hundred eighty-nine million, fifty thousand, five hundred five".