40279861 has 2 divisors, whose sum is σ = 40279862. Its totient is φ = 40279860.

The previous prime is 40279859. The next prime is 40279871. The reversal of 40279861 is 16897204.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39816100 + 463761 = 6310^2 + 681^2 .

It is a cyclic number.

It is not a de Polignac number, because 40279861 - 2¹ = 40279859 is a prime.

Together with 40279859, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 40279861.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40279871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20139930 + 20139931.

It is an arithmetic number, because the mean of its divisors is an integer number (20139931).

Almost surely, 2^40279861 is an apocalyptic number.

It is an amenable number.

40279861 is a deficient number, since it is larger than the sum of its proper divisors (1).

40279861 is an equidigital number, since it uses as much as digits as its factorization.

40279861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 40279861 is about 6346.6417103851. The cubic root of 40279861 is about 342.7909290371.

The spelling of 40279861 in words is "forty million, two hundred seventy-nine thousand, eight hundred sixty-one".