20211457 has 16 divisors (see below), whose sum is σ = 24625152. Its totient is φ = 16212240.

The previous prime is 20211407. The next prime is 20211461. The reversal of 20211457 is 75411202.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-20211457 is a prime.

It is a Duffinian number.

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

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6232 + ... + 8902.

It is an arithmetic number, because the mean of its divisors is an integer number (1539072).

Almost surely, 2^20211457 is an apocalyptic number.

It is an amenable number.

20211457 is a deficient number, since it is larger than the sum of its proper divisors (4413695).

20211457 is a wasteful number, since it uses less digits than its factorization.

20211457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2748.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 20211457 is about 4495.7154046937. The cubic root of 20211457 is about 272.3950475387.

Adding to 20211457 its reverse (75411202), we get a palindrome (95622659).

The spelling of 20211457 in words is "twenty million, two hundred eleven thousand, four hundred fifty-seven".