20547496381 has 2 divisors, whose sum is σ = 20547496382. Its totient is φ = 20547496380.

The previous prime is 20547496309. The next prime is 20547496391. The reversal of 20547496381 is 18369474502.

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., 16876348281 + 3671148100 = 129909^2 + 60590^2 .

It is a cyclic number.

It is not a de Polignac number, because 20547496381 - 2¹⁷ = 20547365309 is a prime.

It is a super-2 number, since 2×20547496381² (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 (20547496391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10273748190 + 10273748191.

It is an arithmetic number, because the mean of its divisors is an integer number (10273748191).

It is a 1-persistent number, because it is pandigital, but 2⋅20547496381 = 41094992762 is not.

Almost surely, 2^20547496381 is an apocalyptic number.

It is an amenable number.

20547496381 is a deficient number, since it is larger than the sum of its proper divisors (1).

20547496381 is an equidigital number, since it uses as much as digits as its factorization.

20547496381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1451520, while the sum is 49.

The spelling of 20547496381 in words is "twenty billion, five hundred forty-seven million, four hundred ninety-six thousand, three hundred eighty-one".