20281937 has 4 divisors (see below), whose sum is σ = 21842100. Its totient is φ = 18721776.

The previous prime is 20281913. The next prime is 20281973. The reversal of 20281937 is 73918202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 73918202 = 2 ⋅36959101.

It can be written as a sum of positive squares in 2 ways, for example, as 8059921 + 12222016 = 2839^2 + 3496^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20281937 is a prime.

It is a super-2 number, since 2×20281937² = 822713936943938, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20281997) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 780062 + ... + 780087.

It is an arithmetic number, because the mean of its divisors is an integer number (5460525).

Almost surely, 2^20281937 is an apocalyptic number.

It is an amenable number.

20281937 is a deficient number, since it is larger than the sum of its proper divisors (1560163).

20281937 is a wasteful number, since it uses less digits than its factorization.

20281937 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1560162.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 20281937 is about 4503.5471575193. The cubic root of 20281937 is about 272.7113059575.

The spelling of 20281937 in words is "twenty million, two hundred eighty-one thousand, nine hundred thirty-seven".