20211408 has 60 divisors (see below), whose sum is σ = 64647648. Its totient is φ = 5774400.

The previous prime is 20211407. The next prime is 20211461. The reversal of 20211408 is 80411202.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9018 + ... + 11033.

Almost surely, 2^20211408 is an apocalyptic number.

20211408 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20211408 is an abundant number, since it is smaller than the sum of its proper divisors (44436240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20211408 is a wasteful number, since it uses less digits than its factorization.

20211408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20072 (or 20063 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 20211408 is about 4495.7099550572. The cubic root of 20211408 is about 272.3948274099.

The spelling of 20211408 in words is "twenty million, two hundred eleven thousand, four hundred eight".