20021355 has 24 divisors (see below), whose sum is σ = 35296560. Its totient is φ = 10495680.

The previous prime is 20021341. The next prime is 20021357. The reversal of 20021355 is 55312002.

It is a happy number.

It is not a de Polignac number, because 20021355 - 2¹⁰ = 20020331 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20021357) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1116 + ... + 6425.

It is an arithmetic number, because the mean of its divisors is an integer number (1470690).

Almost surely, 2^20021355 is an apocalyptic number.

20021355 is a deficient number, since it is larger than the sum of its proper divisors (15275205).

20021355 is a wasteful number, since it uses less digits than its factorization.

20021355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7611 (or 7608 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 18.

The square root of 20021355 is about 4474.5228795929. The cubic root of 20021355 is about 271.5383379415.

Adding to 20021355 its reverse (55312002), we get a palindrome (75333357).

The spelling of 20021355 in words is "twenty million, twenty-one thousand, three hundred fifty-five".