40015021 has 4 divisors (see below), whose sum is σ = 40128732. Its totient is φ = 39901312.

The previous prime is 40014977. The next prime is 40015049. The reversal of 40015021 is 12051004.

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 6502500 + 33512521 = 2550^2 + 5789^2 .

It is a cyclic number.

It is not a de Polignac number, because 40015021 - 2¹³ = 40006829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40014992 and 40015010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40015081) 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, 56326 + ... + 57031.

It is an arithmetic number, because the mean of its divisors is an integer number (10032183).

Almost surely, 2^40015021 is an apocalyptic number.

It is an amenable number.

40015021 is a deficient number, since it is larger than the sum of its proper divisors (113711).

40015021 is a wasteful number, since it uses less digits than its factorization.

40015021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113710.

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 40015021 is about 6325.7427231907. The cubic root of 40015021 is about 342.0379932256.

Adding to 40015021 its reverse (12051004), we get a palindrome (52066025).

The spelling of 40015021 in words is "forty million, fifteen thousand, twenty-one".