20966551680 has 128 divisors (see below), whose sum is σ = 70348420800. Its totient is φ = 5296803840.

The previous prime is 20966551663. The next prime is 20966551681. The reversal of 20966551680 is 8615566902.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×20966551680² (a number of 21 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (48) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (20966551681) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 250891 + ... + 323850.

Almost surely, 2^20966551680 is an apocalyptic number.

20966551680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20966551680 is an abundant number, since it is smaller than the sum of its proper divisors (49381869120).

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

20966551680 is a wasteful number, since it uses less digits than its factorization.

20966551680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 574782 (or 574770 counting only the distinct ones).

The product of its (nonzero) digits is 777600, while the sum is 48.

The spelling of 20966551680 in words is "twenty billion, nine hundred sixty-six million, five hundred fifty-one thousand, six hundred eighty".