21227807 has 4 divisors (see below), whose sum is σ = 22345080. Its totient is φ = 20110536.

The previous prime is 21227783. The next prime is 21227819. The reversal of 21227807 is 70872212.

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 21227807 - 2¹² = 21223711 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 21227807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21227867) 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, 558608 + ... + 558645.

It is an arithmetic number, because the mean of its divisors is an integer number (5586270).

Almost surely, 2^21227807 is an apocalyptic number.

21227807 is a deficient number, since it is larger than the sum of its proper divisors (1117273).

21227807 is a wasteful number, since it uses less digits than its factorization.

21227807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1117272.

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 21227807 is about 4607.3644309952. The cubic root of 21227807 is about 276.8864544380.

The spelling of 21227807 in words is "twenty-one million, two hundred twenty-seven thousand, eight hundred seven".