20401133981 has 2 divisors, whose sum is σ = 20401133982. Its totient is φ = 20401133980.

The previous prime is 20401133969. The next prime is 20401134031. The reversal of 20401133981 is 18933110402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15809038756 + 4592095225 = 125734^2 + 67765^2 .

It is a cyclic number.

It is not a de Polignac number, because 20401133981 - 2¹⁸ = 20400871837 is a prime.

It is a super-2 number, since 2×20401133981² (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 (20401133911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10200566990 + 10200566991.

It is an arithmetic number, because the mean of its divisors is an integer number (10200566991).

Almost surely, 2^20401133981 is an apocalyptic number.

It is an amenable number.

20401133981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20401133981 is an equidigital number, since it uses as much as digits as its factorization.

20401133981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 32.

The spelling of 20401133981 in words is "twenty billion, four hundred one million, one hundred thirty-three thousand, nine hundred eighty-one".