40721789 has 2 divisors, whose sum is σ = 40721790. Its totient is φ = 40721788.

The previous prime is 40721777. The next prime is 40721797. The reversal of 40721789 is 98712704.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34421689 + 6300100 = 5867^2 + 2510^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40721789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40721089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20360894 + 20360895.

It is an arithmetic number, because the mean of its divisors is an integer number (20360895).

Almost surely, 2^40721789 is an apocalyptic number.

It is an amenable number.

40721789 is a deficient number, since it is larger than the sum of its proper divisors (1).

40721789 is an equidigital number, since it uses as much as digits as its factorization.

40721789 is an odious number, because the sum of its binary digits is odd.

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

The square root of 40721789 is about 6381.3626287808. The cubic root of 40721789 is about 344.0400085295.

The spelling of 40721789 in words is "forty million, seven hundred twenty-one thousand, seven hundred eighty-nine".