20120009981 has 2 divisors, whose sum is σ = 20120009982. Its totient is φ = 20120009980.

The previous prime is 20120009953. The next prime is 20120010007. The reversal of 20120009981 is 18990002102.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16611343225 + 3508666756 = 128885^2 + 59234^2 .

It is a cyclic number.

It is not a de Polignac number, because 20120009981 - 2²² = 20115815677 is a prime.

It is a super-2 number, since 2×20120009981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20120009941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060004990 + 10060004991.

It is an arithmetic number, because the mean of its divisors is an integer number (10060004991).

Almost surely, 2^20120009981 is an apocalyptic number.

It is an amenable number.

20120009981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20120009981 is an equidigital number, since it uses as much as digits as its factorization.

20120009981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 32.

The spelling of 20120009981 in words is "twenty billion, one hundred twenty million, nine thousand, nine hundred eighty-one".