20221815 has 32 divisors (see below), whose sum is σ = 33530112. Its totient is φ = 10400000.

The previous prime is 20221811. The next prime is 20221819. The reversal of 20221815 is 51812202.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20221811) and next prime (20221819).

It is not a de Polignac number, because 20221815 - 2² = 20221811 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20221791 and 20221800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20221811) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 80440 + ... + 80690.

It is an arithmetic number, because the mean of its divisors is an integer number (1047816).

Almost surely, 2^20221815 is an apocalyptic number.

20221815 is a deficient number, since it is larger than the sum of its proper divisors (13308297).

20221815 is a wasteful number, since it uses less digits than its factorization.

20221815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 431.

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 20221815 is about 4496.8672428703. The cubic root of 20221815 is about 272.4415720760.

The spelling of 20221815 in words is "twenty million, two hundred twenty-one thousand, eight hundred fifteen".