20751168921 has 16 divisors (see below), whose sum is σ = 32711203200. Its totient is φ = 11448920448.

The previous prime is 20751168871. The next prime is 20751168923. The reversal of 20751168921 is 12986115702.

It is not a de Polignac number, because 20751168921 - 2¹⁰ = 20751167897 is a prime.

It is a super-2 number, since 2×20751168921² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20751168923) 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, 17036476 + ... + 17037693.

It is an arithmetic number, because the mean of its divisors is an integer number (2044450200).

Almost surely, 2^20751168921 is an apocalyptic number.

20751168921 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20751168921 is a deficient number, since it is larger than the sum of its proper divisors (11960034279).

20751168921 is a wasteful number, since it uses less digits than its factorization.

20751168921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34074208.

The product of its (nonzero) digits is 60480, while the sum is 42.

The spelling of 20751168921 in words is "twenty billion, seven hundred fifty-one million, one hundred sixty-eight thousand, nine hundred twenty-one".