21034556 has 6 divisors (see below), whose sum is σ = 36810480. Its totient is φ = 10517276.

The previous prime is 21034543. The next prime is 21034561. The reversal of 21034556 is 65543012.

It is a super-2 number, since 2×21034556² = 884905092234272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2629316 + ... + 2629323.

It is an arithmetic number, because the mean of its divisors is an integer number (6135080).

Almost surely, 2^21034556 is an apocalyptic number.

It is an amenable number.

21034556 is a deficient number, since it is larger than the sum of its proper divisors (15775924).

21034556 is a wasteful number, since it uses less digits than its factorization.

21034556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5258643 (or 5258641 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 21034556 is about 4586.3445138803. The cubic root of 21034556 is about 276.0436638894.

Adding to 21034556 its reverse (65543012), we get a palindrome (86577568).

The spelling of 21034556 in words is "twenty-one million, thirty-four thousand, five hundred fifty-six".