20387629 has 4 divisors (see below), whose sum is σ = 20938684. Its totient is φ = 19836576.

The previous prime is 20387623. The next prime is 20387651. The reversal of 20387629 is 92678302.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 19377604 + 1010025 = 4402^2 + 1005^2 .

It is a cyclic number.

It is not a de Polignac number, because 20387629 - 2³ = 20387621 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37), and also a Moran number because the ratio is a prime number: 551017 = 20387629 / (2 + 0 + 3 + 8 + 7 + 6 + 2 + 9).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20387621) 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, 275472 + ... + 275545.

It is an arithmetic number, because the mean of its divisors is an integer number (5234671).

Almost surely, 2^20387629 is an apocalyptic number.

It is an amenable number.

20387629 is a deficient number, since it is larger than the sum of its proper divisors (551055).

20387629 is an equidigital number, since it uses as much as digits as its factorization.

20387629 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 551054.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 20387629 is about 4515.2662158504. The cubic root of 20387629 is about 273.1841976773.

The spelling of 20387629 in words is "twenty million, three hundred eighty-seven thousand, six hundred twenty-nine".