20402451 has 12 divisors (see below), whose sum is σ = 29687112. Its totient is φ = 13501536.

The previous prime is 20402443. The next prime is 20402467. The reversal of 20402451 is 15420402.

It is not a de Polignac number, because 20402451 - 2³ = 20402443 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20402411) 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, 7041 + ... + 9506.

It is an arithmetic number, because the mean of its divisors is an integer number (2473926).

Almost surely, 2^20402451 is an apocalyptic number.

20402451 is a deficient number, since it is larger than the sum of its proper divisors (9284661).

20402451 is a wasteful number, since it uses less digits than its factorization.

20402451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16690 (or 16687 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 20402451 is about 4516.9072383656. The cubic root of 20402451 is about 273.2503841430.

Adding to 20402451 its reverse (15420402), we get a palindrome (35822853).

The spelling of 20402451 in words is "twenty million, four hundred two thousand, four hundred fifty-one".