21073811 has 8 divisors (see below), whose sum is σ = 23029248. Its totient is φ = 19125000.

The previous prime is 21073799. The next prime is 21073837. The reversal of 21073811 is 11837012.

It is a happy number.

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 21073811 - 2¹⁴ = 21057427 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21073891) 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, 6986 + ... + 9536.

It is an arithmetic number, because the mean of its divisors is an integer number (2878656).

Almost surely, 2^21073811 is an apocalyptic number.

21073811 is a deficient number, since it is larger than the sum of its proper divisors (1955437).

21073811 is a wasteful number, since it uses less digits than its factorization.

21073811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3313.

The product of its (nonzero) digits is 336, while the sum is 23.

The square root of 21073811 is about 4590.6220711359. The cubic root of 21073811 is about 276.2152761034.

The spelling of 21073811 in words is "twenty-one million, seventy-three thousand, eight hundred eleven".