20791487 has 2 divisors, whose sum is σ = 20791488. Its totient is φ = 20791486.

The previous prime is 20791451. The next prime is 20791501. The reversal of 20791487 is 78419702.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20791487 - 2¹⁴ = 20775103 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20791487.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20791087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10395743 + 10395744.

It is an arithmetic number, because the mean of its divisors is an integer number (10395744).

Almost surely, 2^20791487 is an apocalyptic number.

20791487 is a deficient number, since it is larger than the sum of its proper divisors (1).

20791487 is an equidigital number, since it uses as much as digits as its factorization.

20791487 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 20791487 is about 4559.7683055173. The cubic root of 20791487 is about 274.9762491885.

The spelling of 20791487 in words is "twenty million, seven hundred ninety-one thousand, four hundred eighty-seven".