20510397 has 12 divisors (see below), whose sum is σ = 29692000. Its totient is φ = 13643208.

The previous prime is 20510393. The next prime is 20510419. The reversal of 20510397 is 79301502.

It is not a de Polignac number, because 20510397 - 2² = 20510393 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20510397.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20510393) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2208 + ... + 6774.

Almost surely, 2^20510397 is an apocalyptic number.

It is an amenable number.

20510397 is a deficient number, since it is larger than the sum of its proper divisors (9181603).

20510397 is a wasteful number, since it uses less digits than its factorization.

20510397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5072 (or 5069 counting only the distinct ones).

The product of its (nonzero) digits is 1890, while the sum is 27.

The square root of 20510397 is about 4528.8405801044. The cubic root of 20510397 is about 273.7314442918.

Adding to 20510397 its reverse (79301502), we get a palindrome (99811899).

The spelling of 20510397 in words is "twenty million, five hundred ten thousand, three hundred ninety-seven".