66402420 has 96 divisors (see below), whose sum is σ = 218281728. Its totient is φ = 14764032.

The previous prime is 66402419. The next prime is 66402433. The reversal of 66402420 is 2420466.

It is a super-4 number, since 4×66402420⁴ (a number of 32 digits) contains 4444 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13404 + ... + 17676.

It is an arithmetic number, because the mean of its divisors is an integer number (2273768).

Almost surely, 2^66402420 is an apocalyptic number.

66402420 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66402420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109140864).

66402420 is an abundant number, since it is smaller than the sum of its proper divisors (151879308).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66402420 is a wasteful number, since it uses less digits than its factorization.

66402420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4329 (or 4327 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 66402420 is about 8148.7680050422. The cubic root of 66402420 is about 404.9436897782.

Adding to 66402420 its reverse (2420466), we get a palindrome (68822886).

The spelling of 66402420 in words is "sixty-six million, four hundred two thousand, four hundred twenty".