40101821 has 4 divisors (see below), whose sum is σ = 41185692. Its totient is φ = 39017952.

The previous prime is 40101797. The next prime is 40101823. The reversal of 40101821 is 12810104.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 37576900 + 2524921 = 6130^2 + 1589^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40101821 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 40101821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40101823) 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 in 3 ways as a sum of consecutive naturals, for example, 541880 + ... + 541953.

It is an arithmetic number, because the mean of its divisors is an integer number (10296423).

Almost surely, 2^40101821 is an apocalyptic number.

It is an amenable number.

40101821 is a deficient number, since it is larger than the sum of its proper divisors (1083871).

40101821 is a wasteful number, since it uses less digits than its factorization.

40101821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1083870.

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 40101821 is about 6332.5998610365. The cubic root of 40101821 is about 342.2851292260.

Adding to 40101821 its reverse (12810104), we get a palindrome (52911925).

The spelling of 40101821 in words is "forty million, one hundred one thousand, eight hundred twenty-one".