20198537 has 4 divisors (see below), whose sum is σ = 20285460. Its totient is φ = 20111616.

The previous prime is 20198513. The next prime is 20198543. The reversal of 20198537 is 73589102.

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 2524921 + 17673616 = 1589^2 + 4204^2 .

It is a cyclic number.

It is not a de Polignac number, because 20198537 - 2²⁴ = 3421321 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20198497 and 20198506.

It is not an unprimeable number, because it can be changed into a prime (20198837) 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, 43112 + ... + 43577.

It is an arithmetic number, because the mean of its divisors is an integer number (5071365).

Almost surely, 2^20198537 is an apocalyptic number.

It is an amenable number.

20198537 is a deficient number, since it is larger than the sum of its proper divisors (86923).

20198537 is an equidigital number, since it uses as much as digits as its factorization.

20198537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86922.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 20198537 is about 4494.2782512880. The cubic root of 20198537 is about 272.3369931031.

The spelling of 20198537 in words is "twenty million, one hundred ninety-eight thousand, five hundred thirty-seven".