21451011 has 8 divisors (see below), whose sum is σ = 28695744. Its totient is φ = 14253480.

The previous prime is 21451007. The next prime is 21451013. The reversal of 21451011 is 11015412.

It is a happy number.

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

It is not a de Polignac number, because 21451011 - 2² = 21451007 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21451013) 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, 10725 + ... + 12566.

It is an arithmetic number, because the mean of its divisors is an integer number (3586968).

Almost surely, 2^21451011 is an apocalyptic number.

21451011 is a deficient number, since it is larger than the sum of its proper divisors (7244733).

21451011 is a wasteful number, since it uses less digits than its factorization.

21451011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23601.

The product of its (nonzero) digits is 40, while the sum is 15.

The square root of 21451011 is about 4631.5236153991. The cubic root of 21451011 is about 277.8535320440.

Adding to 21451011 its reverse (11015412), we get a palindrome (32466423).

The spelling of 21451011 in words is "twenty-one million, four hundred fifty-one thousand, eleven".