20421346 has 16 divisors (see below), whose sum is σ = 33684480. Its totient is φ = 9208080.

The previous prime is 20421337. The next prime is 20421347. The reversal of 20421346 is 64312402.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (20421347) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 861 + ... + 6448.

It is an arithmetic number, because the mean of its divisors is an integer number (2105280).

Almost surely, 2^20421346 is an apocalyptic number.

20421346 is a deficient number, since it is larger than the sum of its proper divisors (13263134).

20421346 is a wasteful number, since it uses less digits than its factorization.

20421346 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7449.

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 20421346 is about 4518.9983403405. The cubic root of 20421346 is about 273.3347118048.

Adding to 20421346 its reverse (64312402), we get a palindrome (84733748).

The spelling of 20421346 in words is "twenty million, four hundred twenty-one thousand, three hundred forty-six".