40221521 has 4 divisors (see below), whose sum is σ = 41608500. Its totient is φ = 38834544.

The previous prime is 40221487. The next prime is 40221523. The reversal of 40221521 is 12512204.

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 20070400 + 20151121 = 4480^2 + 4489^2 .

It is a cyclic number.

It is not a de Polignac number, because 40221521 - 2¹⁰ = 40220497 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 40221521.

It is not an unprimeable number, because it can be changed into a prime (40221523) 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, 693446 + ... + 693503.

It is an arithmetic number, because the mean of its divisors is an integer number (10402125).

Almost surely, 2^40221521 is an apocalyptic number.

It is an amenable number.

40221521 is a deficient number, since it is larger than the sum of its proper divisors (1386979).

40221521 is a wasteful number, since it uses less digits than its factorization.

40221521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1386978.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 40221521 is about 6342.0439134399. The cubic root of 40221521 is about 342.6253534443.

Adding to 40221521 its reverse (12512204), we get a palindrome (52733725).

The spelling of 40221521 in words is "forty million, two hundred twenty-one thousand, five hundred twenty-one".