20451407 has 2 divisors, whose sum is σ = 20451408. Its totient is φ = 20451406.

The previous prime is 20451397. The next prime is 20451437. The reversal of 20451407 is 70415402.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20451407 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20451437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10225703 + 10225704.

It is an arithmetic number, because the mean of its divisors is an integer number (10225704).

Almost surely, 2^20451407 is an apocalyptic number.

20451407 is a deficient number, since it is larger than the sum of its proper divisors (1).

20451407 is an equidigital number, since it uses as much as digits as its factorization.

20451407 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1120, while the sum is 23.

The square root of 20451407 is about 4522.3231861511. The cubic root of 20451407 is about 273.4687657549.

Adding to 20451407 its reverse (70415402), we get a palindrome (90866809).

The spelling of 20451407 in words is "twenty million, four hundred fifty-one thousand, four hundred seven".