20401577 has 4 divisors (see below), whose sum is σ = 23316096. Its totient is φ = 17487060.

The previous prime is 20401571. The next prime is 20401603. The reversal of 20401577 is 77510402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 77510402 = 2 ⋅38755201.

It is a cyclic number.

It is not a de Polignac number, because 20401577 - 2⁴ = 20401561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20401571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1457249 + ... + 1457262.

It is an arithmetic number, because the mean of its divisors is an integer number (5829024).

Almost surely, 2^20401577 is an apocalyptic number.

It is an amenable number.

20401577 is a deficient number, since it is larger than the sum of its proper divisors (2914519).

20401577 is an equidigital number, since it uses as much as digits as its factorization.

20401577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2914518.

The product of its (nonzero) digits is 1960, while the sum is 26.

The square root of 20401577 is about 4516.8104897151. The cubic root of 20401577 is about 273.2464822548.

Adding to 20401577 its reverse (77510402), we get a palindrome (97911979).

The spelling of 20401577 in words is "twenty million, four hundred one thousand, five hundred seventy-seven".