28790561381 has 2 divisors, whose sum is σ = 28790561382. Its totient is φ = 28790561380.

The previous prime is 28790561347. The next prime is 28790561407. The reversal of 28790561381 is 18316509782.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24817276225 + 3973285156 = 157535^2 + 63034^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28790561381 is a prime.

It is a super-2 number, since 2×28790561381² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28790561081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14395280690 + 14395280691.

It is an arithmetic number, because the mean of its divisors is an integer number (14395280691).

Almost surely, 2^28790561381 is an apocalyptic number.

It is an amenable number.

28790561381 is a deficient number, since it is larger than the sum of its proper divisors (1).

28790561381 is an equidigital number, since it uses as much as digits as its factorization.

28790561381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 725760, while the sum is 50.

The spelling of 28790561381 in words is "twenty-eight billion, seven hundred ninety million, five hundred sixty-one thousand, three hundred eighty-one".