20401457 has 2 divisors, whose sum is σ = 20401458. Its totient is φ = 20401456.

The previous prime is 20401453. The next prime is 20401463. The reversal of 20401457 is 75410402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19722481 + 678976 = 4441^2 + 824^2 .

It is a cyclic number.

It is not a de Polignac number, because 20401457 - 2² = 20401453 is a prime.

It is not a weakly prime, because it can be changed into another prime (20401453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10200728 + 10200729.

It is an arithmetic number, because the mean of its divisors is an integer number (10200729).

Almost surely, 2^20401457 is an apocalyptic number.

It is an amenable number.

20401457 is a deficient number, since it is larger than the sum of its proper divisors (1).

20401457 is an equidigital number, since it uses as much as digits as its factorization.

20401457 is an odious number, because the sum of its binary digits is odd.

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

The square root of 20401457 is about 4516.7972059857. The cubic root of 20401457 is about 273.2459465178.

Adding to 20401457 its reverse (75410402), we get a palindrome (95811859).

The spelling of 20401457 in words is "twenty million, four hundred one thousand, four hundred fifty-seven".