21213034 has 4 divisors (see below), whose sum is σ = 31819554. Its totient is φ = 10606516.

The previous prime is 21213029. The next prime is 21213041. The reversal of 21213034 is 43031212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20223009 + 990025 = 4497^2 + 995^2 .

It is a super-2 number, since 2×21213034² = 899985622970312, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21212999 and 21213017.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5303257 + ... + 5303260.

Almost surely, 2^21213034 is an apocalyptic number.

21213034 is a deficient number, since it is larger than the sum of its proper divisors (10606520).

21213034 is a wasteful number, since it uses less digits than its factorization.

21213034 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10606519.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 21213034 is about 4605.7609577571. The cubic root of 21213034 is about 276.8222086299.

Adding to 21213034 its reverse (43031212), we get a palindrome (64244246).

The spelling of 21213034 in words is "twenty-one million, two hundred thirteen thousand, thirty-four".