20405007 has 32 divisors (see below), whose sum is σ = 34905600. Its totient is φ = 11539584.

The previous prime is 20404999. The next prime is 20405027. The reversal of 20405007 is 70050402.

It is a happy number.

It is not a de Polignac number, because 20405007 - 2³ = 20404999 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20405027) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19719 + ... + 20727.

It is an arithmetic number, because the mean of its divisors is an integer number (1090800).

Almost surely, 2^20405007 is an apocalyptic number.

20405007 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

20405007 is a deficient number, since it is larger than the sum of its proper divisors (14500593).

20405007 is a wasteful number, since it uses less digits than its factorization.

20405007 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1132 (or 1126 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 18.

The square root of 20405007 is about 4517.1901664641. The cubic root of 20405007 is about 273.2617945174.

Adding to 20405007 its reverse (70050402), we get a palindrome (90455409).

The spelling of 20405007 in words is "twenty million, four hundred five thousand, seven".