33640421 has 4 divisors (see below), whose sum is σ = 35103072. Its totient is φ = 32177772.

The previous prime is 33640417. The next prime is 33640423. The reversal of 33640421 is 12404633.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12404633 = 337 ⋅36809.

It is a cyclic number.

It is not a de Polignac number, because 33640421 - 2² = 33640417 is a prime.

It is a super-2 number, since 2×33640421² = 2263355850114482, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 1462627 = 33640421 / (3 + 3 + 6 + 4 + 0 + 4 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33640423) 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, 731291 + ... + 731336.

It is an arithmetic number, because the mean of its divisors is an integer number (8775768).

Almost surely, 2^33640421 is an apocalyptic number.

It is an amenable number.

33640421 is a deficient number, since it is larger than the sum of its proper divisors (1462651).

33640421 is a wasteful number, since it uses less digits than its factorization.

33640421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1462650.

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 33640421 is about 5800.0362929899. The cubic root of 33640421 is about 322.8150749685.

The spelling of 33640421 in words is "thirty-three million, six hundred forty thousand, four hundred twenty-one".