355000021 has 4 divisors (see below), whose sum is σ = 355038444. Its totient is φ = 354961600.

The previous prime is 355000007. The next prime is 355000027. The reversal of 355000021 is 120000553.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 120000553 = 211 ⋅568723.

It can be written as a sum of positive squares in 2 ways, for example, as 156500100 + 198499921 = 12510^2 + 14089^2 .

It is a cyclic number.

It is not a de Polignac number, because 355000021 - 2⁷ = 354999893 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 354999959 and 355000004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (355000027) 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, 3981 + ... + 26941.

It is an arithmetic number, because the mean of its divisors is an integer number (88759611).

Almost surely, 2^355000021 is an apocalyptic number.

It is an amenable number.

355000021 is a deficient number, since it is larger than the sum of its proper divisors (38423).

355000021 is a wasteful number, since it uses less digits than its factorization.

355000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38422.

The product of its (nonzero) digits is 150, while the sum is 16.

The square root of 355000021 is about 18841.4442386989. Note that the first 3 decimals coincide. The cubic root of 355000021 is about 708.0698890704.

Adding to 355000021 its reverse (120000553), we get a palindrome (475000574).

The spelling of 355000021 in words is "three hundred fifty-five million, twenty-one", and thus it is an aban number.