20401501 has 2 divisors, whose sum is σ = 20401502. Its totient is φ = 20401500.

The previous prime is 20401499. The next prime is 20401523. The reversal of 20401501 is 10510402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13505625 + 6895876 = 3675^2 + 2626^2 .

It is a cyclic number.

It is not a de Polignac number, because 20401501 - 2¹ = 20401499 is a prime.

Together with 20401499, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20401561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10200750 + 10200751.

It is an arithmetic number, because the mean of its divisors is an integer number (10200751).

Almost surely, 2^20401501 is an apocalyptic number.

It is an amenable number.

20401501 is a deficient number, since it is larger than the sum of its proper divisors (1).

20401501 is an equidigital number, since it uses as much as digits as its factorization.

20401501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 20401501 is about 4516.8020766910. The cubic root of 20401501 is about 273.2461429549.

Adding to 20401501 its reverse (10510402), we get a palindrome (30911903).

It can be divided in two parts, 20401 and 501, that added together give a palindrome (20902).

The spelling of 20401501 in words is "twenty million, four hundred one thousand, five hundred one".