20401493 has 12 divisors (see below), whose sum is σ = 23820300. Its totient is φ = 17422272.

The previous prime is 20401489. The next prime is 20401499. The reversal of 20401493 is 39410402.

It can be written as a sum of positive squares in 2 ways, for example, as 12794929 + 7606564 = 3577^2 + 2758^2 .

It is not a de Polignac number, because 20401493 - 2² = 20401489 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20401499) 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, 16505 + ... + 17697.

It is an arithmetic number, because the mean of its divisors is an integer number (1985025).

Almost surely, 2^20401493 is an apocalyptic number.

It is an amenable number.

20401493 is a deficient number, since it is larger than the sum of its proper divisors (3418807).

20401493 is a wasteful number, since it uses less digits than its factorization.

20401493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1556 (or 1549 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 20401493 is about 4516.8011911086. The cubic root of 20401493 is about 273.2461072391.

Adding to 20401493 its reverse (39410402), we get a palindrome (59811895).

The spelling of 20401493 in words is "twenty million, four hundred one thousand, four hundred ninety-three".