40200021 has 12 divisors (see below), whose sum is σ = 60591648. Its totient is φ = 25634664.

The previous prime is 40199983. The next prime is 40200071. The reversal of 40200021 is 12000204.

It is not a de Polignac number, because 40200021 - 2¹⁹ = 39675733 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 40199976 and 40200012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40200071) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 96895 + ... + 97308.

It is an arithmetic number, because the mean of its divisors is an integer number (5049304).

Almost surely, 2^40200021 is an apocalyptic number.

It is an amenable number.

40200021 is a deficient number, since it is larger than the sum of its proper divisors (20391627).

40200021 is a wasteful number, since it uses less digits than its factorization.

40200021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194232 (or 194229 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

The square root of 40200021 is about 6340.3486497195. The cubic root of 40200021 is about 342.5642936115.

Adding to 40200021 its reverse (12000204), we get a palindrome (52200225).

The spelling of 40200021 in words is "forty million, two hundred thousand, twenty-one".