1401639 has 4 divisors (see below), whose sum is σ = 1868856. Its totient is φ = 934424.

The previous prime is 1401629. The next prime is 1401641. The reversal of 1401639 is 9361041.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1401639 - 2⁴ = 1401623 is a prime.

It is a D-number.

1401639 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1401629) 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 3 ways as a sum of consecutive naturals, for example, 233604 + ... + 233609.

It is an arithmetic number, because the mean of its divisors is an integer number (467214).

2^1401639 is an apocalyptic number.

1401639 is a deficient number, since it is larger than the sum of its proper divisors (467217).

1401639 is an equidigital number, since it uses as much as digits as its factorization.

1401639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 467216.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 1401639 is about 1183.9083579399. The cubic root of 1401639 is about 111.9125326874.

The spelling of 1401639 in words is "one million, four hundred one thousand, six hundred thirty-nine".