21034951 has 4 divisors (see below), whose sum is σ = 24039952. Its totient is φ = 18029952.

The previous prime is 21034943. The next prime is 21034963. The reversal of 21034951 is 15943012.

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

It is a cyclic number.

It is not a de Polignac number, because 21034951 - 2³ = 21034943 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21034751) 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, 1502490 + ... + 1502503.

It is an arithmetic number, because the mean of its divisors is an integer number (6009988).

Almost surely, 2^21034951 is an apocalyptic number.

21034951 is a deficient number, since it is larger than the sum of its proper divisors (3005001).

21034951 is an equidigital number, since it uses as much as digits as its factorization.

21034951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3005000.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 21034951 is about 4586.3875762957. The cubic root of 21034951 is about 276.0453917852.

Adding to 21034951 its reverse (15943012), we get a palindrome (36977963).

The spelling of 21034951 in words is "twenty-one million, thirty-four thousand, nine hundred fifty-one".