66100401 has 32 divisors (see below), whose sum is σ = 101949440. Its totient is φ = 42282000.

The previous prime is 66100351. The next prime is 66100429. The reversal of 66100401 is 10400166.

66100401 is a `hidden beast` number, since 661 + 0 + 0 + 4 + 0 + 1 = 666.

It is not a de Polignac number, because 66100401 - 2⁷ = 66100273 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66100501) 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, 126126 + ... + 126648.

It is an arithmetic number, because the mean of its divisors is an integer number (3185920).

Almost surely, 2^66100401 is an apocalyptic number.

It is an amenable number.

66100401 is a deficient number, since it is larger than the sum of its proper divisors (35849039).

66100401 is a wasteful number, since it uses less digits than its factorization.

66100401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 714 (or 708 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 66100401 is about 8130.2153108020. The cubic root of 66100401 is about 404.3288197237.

Adding to 66100401 its reverse (10400166), we get a palindrome (76500567).

It can be divided in two parts, 6610040 and 1, that added together give a square (6610041 = 2571²).

The spelling of 66100401 in words is "sixty-six million, one hundred thousand, four hundred one".