66402401 has 8 divisors (see below), whose sum is σ = 71985984. Its totient is φ = 60886800.

The previous prime is 66402367. The next prime is 66402409. The reversal of 66402401 is 10420466.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66402401 - 2⁶ = 66402337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66402409) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14951 + ... + 18876.

It is an arithmetic number, because the mean of its divisors is an integer number (8998248).

Almost surely, 2^66402401 is an apocalyptic number.

It is an amenable number.

66402401 is a deficient number, since it is larger than the sum of its proper divisors (5583583).

66402401 is a wasteful number, since it uses less digits than its factorization.

66402401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33991.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 66402401 is about 8148.7668392217. The cubic root of 66402401 is about 404.9436511555.

Adding to 66402401 its reverse (10420466), we get a palindrome (76822867).

The spelling of 66402401 in words is "sixty-six million, four hundred two thousand, four hundred one".