20440388 has 6 divisors (see below), whose sum is σ = 35770686. Its totient is φ = 10220192.

The previous prime is 20440379. The next prime is 20440397. The reversal of 20440388 is 88304402.

It is an interprime number because it is at equal distance from previous prime (20440379) and next prime (20440397).

It can be written as a sum of positive squares in only one way, i.e., 16630084 + 3810304 = 4078^2 + 1952^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 20440388.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2555045 + ... + 2555052.

It is an arithmetic number, because the mean of its divisors is an integer number (5961781).

Almost surely, 2^20440388 is an apocalyptic number.

It is an amenable number.

20440388 is a deficient number, since it is larger than the sum of its proper divisors (15330298).

20440388 is a wasteful number, since it uses less digits than its factorization.

20440388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5110101 (or 5110099 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 29.

The square root of 20440388 is about 4521.1047322529. The cubic root of 20440388 is about 273.4196429133.

The spelling of 20440388 in words is "twenty million, four hundred forty thousand, three hundred eighty-eight".