20778453 has 12 divisors (see below), whose sum is σ = 31318560. Its totient is φ = 13249896.

The previous prime is 20778449. The next prime is 20778473. The reversal of 20778453 is 35487702.

It is not a de Polignac number, because 20778453 - 2² = 20778449 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20778473) 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, 49983 + ... + 50396.

It is an arithmetic number, because the mean of its divisors is an integer number (2609880).

Almost surely, 2^20778453 is an apocalyptic number.

20778453 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

20778453 is a deficient number, since it is larger than the sum of its proper divisors (10540107).

20778453 is a wasteful number, since it uses less digits than its factorization.

20778453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100408 (or 100405 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 36.

The square root of 20778453 is about 4558.3388421661. The cubic root of 20778453 is about 274.9187771146.

The spelling of 20778453 in words is "twenty million, seven hundred seventy-eight thousand, four hundred fifty-three".