1400128640 has 64 divisors (see below), whose sum is σ = 3455205120. Its totient is φ = 541977600.

The previous prime is 1400128621. The next prime is 1400128643. The reversal of 1400128640 is 468210041.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (1400128643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15446 + ... + 55125.

It is an arithmetic number, because the mean of its divisors is an integer number (53987580).

Almost surely, 2^1400128640 is an apocalyptic number.

1400128640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1400128640 is an abundant number, since it is smaller than the sum of its proper divisors (2055076480).

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

1400128640 is an equidigital number, since it uses as much as digits as its factorization.

1400128640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70621 (or 70609 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 1400128640 is about 37418.2928525608. The cubic root of 1400128640 is about 1118.7232048762.

Adding to 1400128640 its reverse (468210041), we get a palindrome (1868338681).

The spelling of 1400128640 in words is "one billion, four hundred million, one hundred twenty-eight thousand, six hundred forty".