40151821 has 4 divisors (see below), whose sum is σ = 40194144. Its totient is φ = 40109500.

The previous prime is 40151791. The next prime is 40151861. The reversal of 40151821 is 12815104.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 40151821 - 2¹³ = 40143629 is a prime.

It is a super-2 number, since 2×40151821² = 3224337459232082, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40151792 and 40151801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40151861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19705 + ... + 21646.

It is an arithmetic number, because the mean of its divisors is an integer number (10048536).

Almost surely, 2^40151821 is an apocalyptic number.

It is an amenable number.

40151821 is a deficient number, since it is larger than the sum of its proper divisors (42323).

40151821 is an equidigital number, since it uses as much as digits as its factorization.

40151821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42322.

The product of its (nonzero) digits is 320, while the sum is 22.

The square root of 40151821 is about 6336.5464568643. The cubic root of 40151821 is about 342.4273268297.

Adding to 40151821 its reverse (12815104), we get a palindrome (52966925).

The spelling of 40151821 in words is "forty million, one hundred fifty-one thousand, eight hundred twenty-one".