21034691 has 8 divisors (see below), whose sum is σ = 22506000. Its totient is φ = 19599840.

The previous prime is 21034687. The next prime is 21034723. The reversal of 21034691 is 19643012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21034691 - 2² = 21034687 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21034691.

It is not an unprimeable number, because it can be changed into a prime (21034591) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7916 + ... + 10233.

It is an arithmetic number, because the mean of its divisors is an integer number (2813250).

Almost surely, 2^21034691 is an apocalyptic number.

21034691 is a deficient number, since it is larger than the sum of its proper divisors (1471309).

21034691 is a wasteful number, since it uses less digits than its factorization.

21034691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18229.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 21034691 is about 4586.3592314602. The cubic root of 21034691 is about 276.0442544385.

The spelling of 21034691 in words is "twenty-one million, thirty-four thousand, six hundred ninety-one".