40021819 has 2 divisors, whose sum is σ = 40021820. Its totient is φ = 40021818.

The previous prime is 40021789. The next prime is 40021841. The reversal of 40021819 is 91812004.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 40021819 - 2¹³ = 40013627 is a prime.

It is a super-2 number, since 2×40021819² = 3203491992137522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 40021793 and 40021802.

It is not a weakly prime, because it can be changed into another prime (40022819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20010909 + 20010910.

It is an arithmetic number, because the mean of its divisors is an integer number (20010910).

Almost surely, 2^40021819 is an apocalyptic number.

40021819 is a deficient number, since it is larger than the sum of its proper divisors (1).

40021819 is an equidigital number, since it uses as much as digits as its factorization.

40021819 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 40021819 is about 6326.2800285792. The cubic root of 40021819 is about 342.0573613076.

The spelling of 40021819 in words is "forty million, twenty-one thousand, eight hundred nineteen".