20215432381 has 2 divisors, whose sum is σ = 20215432382. Its totient is φ = 20215432380.

The previous prime is 20215432327. The next prime is 20215432417. The reversal of 20215432381 is 18323451202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18249308100 + 1966124281 = 135090^2 + 44341^2 .

It is a cyclic number.

It is not a de Polignac number, because 20215432381 - 2⁷ = 20215432253 is a prime.

It is a super-2 number, since 2×20215432381² (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 (20215432301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10107716190 + 10107716191.

It is an arithmetic number, because the mean of its divisors is an integer number (10107716191).

Almost surely, 2^20215432381 is an apocalyptic number.

It is an amenable number.

20215432381 is a deficient number, since it is larger than the sum of its proper divisors (1).

20215432381 is an equidigital number, since it uses as much as digits as its factorization.

20215432381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11520, while the sum is 31.

Adding to 20215432381 its reverse (18323451202), we get a palindrome (38538883583).

The spelling of 20215432381 in words is "twenty billion, two hundred fifteen million, four hundred thirty-two thousand, three hundred eighty-one".