20472451 has 4 divisors (see below), whose sum is σ = 20610000. Its totient is φ = 20334904.

The previous prime is 20472421. The next prime is 20472467. The reversal of 20472451 is 15427402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15427402 = 2 ⋅7713701.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20472451 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20472421) 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, 68551 + ... + 68848.

It is an arithmetic number, because the mean of its divisors is an integer number (5152500).

Almost surely, 2^20472451 is an apocalyptic number.

20472451 is a deficient number, since it is larger than the sum of its proper divisors (137549).

20472451 is a wasteful number, since it uses less digits than its factorization.

20472451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137548.

The product of its (nonzero) digits is 2240, while the sum is 25.

The square root of 20472451 is about 4524.6492681754. The cubic root of 20472451 is about 273.5625311693.

Adding to 20472451 its reverse (15427402), we get a palindrome (35899853).

The spelling of 20472451 in words is "twenty million, four hundred seventy-two thousand, four hundred fifty-one".