20918415424 has 63 divisors (see below), whose sum is σ = 42160566301. Its totient is φ = 10297798400.

The previous prime is 20918415409. The next prime is 20918415439. The reversal of 20918415424 is 42451481902.

The square root of 20918415424 is 144632.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (20918415409) and next prime (20918415439).

It can be written as a sum of positive squares in only one way, i.e., 20098165824 + 820249600 = 141768^2 + 28640^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 116862567 + ... + 116862745.

Almost surely, 2^20918415424 is an apocalyptic number.

20918415424 is the 144632-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20918415424

20918415424 is an abundant number, since it is smaller than the sum of its proper divisors (21242150877).

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

20918415424 is an frugal number, since it uses more digits than its factorization.

20918415424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 572 (or 282 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 40.

The spelling of 20918415424 in words is "twenty billion, nine hundred eighteen million, four hundred fifteen thousand, four hundred twenty-four".