20401407 has 24 divisors (see below), whose sum is σ = 32008704. Its totient is φ = 12446784.

The previous prime is 20401397. The next prime is 20401427. The reversal of 20401407 is 70410402.

It is a happy number.

It is not a de Polignac number, because 20401407 - 2¹¹ = 20399359 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20401407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20401427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14173 + ... + 15545.

It is an arithmetic number, because the mean of its divisors is an integer number (1333696).

Almost surely, 2^20401407 is an apocalyptic number.

20401407 is a deficient number, since it is larger than the sum of its proper divisors (11607297).

20401407 is a wasteful number, since it uses less digits than its factorization.

20401407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1519 (or 1516 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 18.

The square root of 20401407 is about 4516.7916710869. The cubic root of 20401407 is about 273.2457232934.

Adding to 20401407 its reverse (70410402), we get a palindrome (90811809).

The spelling of 20401407 in words is "twenty million, four hundred one thousand, four hundred seven".