32400021 has 4 divisors (see below), whose sum is σ = 43200032. Its totient is φ = 21600012.

The previous prime is 32400019. The next prime is 32400023. The reversal of 32400021 is 12000423.

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 an interprime number because it is at equal distance from previous prime (32400019) and next prime (32400023).

It is not a de Polignac number, because 32400021 - 2¹ = 32400019 is a prime.

It is a super-2 number, since 2×32400021² = 2099522721600882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (32400023) 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, 5400001 + ... + 5400006.

It is an arithmetic number, because the mean of its divisors is an integer number (10800008).

Almost surely, 2^32400021 is an apocalyptic number.

It is an amenable number.

32400021 is a deficient number, since it is larger than the sum of its proper divisors (10800011).

32400021 is a wasteful number, since it uses less digits than its factorization.

32400021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10800010.

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 32400021 is about 5692.1016329648. The cubic root of 32400021 is about 318.7976396308.

Adding to 32400021 its reverse (12000423), we get a palindrome (44400444).

The spelling of 32400021 in words is "thirty-two million, four hundred thousand, twenty-one".