66431400 has 96 divisors (see below), whose sum is σ = 235371840. Its totient is φ = 15183360.

The previous prime is 66431399. The next prime is 66431441. The reversal of 66431400 is 413466.

It is a super-5 number, since 5×66431400⁵ (a number of 40 digits) contains 55555 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3709 + ... + 12108.

It is an arithmetic number, because the mean of its divisors is an integer number (2451790).

Almost surely, 2^66431400 is an apocalyptic number.

66431400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66431400 is an abundant number, since it is smaller than the sum of its proper divisors (168940440).

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

66431400 is a wasteful number, since it uses less digits than its factorization.

66431400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15843 (or 15834 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 66431400 is about 8150.5459939810. The cubic root of 66431400 is about 405.0025910519.

Adding to 66431400 its reverse (413466), we get a palindrome (66844866).

The spelling of 66431400 in words is "sixty-six million, four hundred thirty-one thousand, four hundred".