901639 has 4 divisors (see below), whose sum is σ = 932760. Its totient is φ = 870520.

The previous prime is 901613. The next prime is 901643. The reversal of 901639 is 936109.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 936109 = 163 ⋅5743.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-901639 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (901679) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15517 + ... + 15574.

It is an arithmetic number, because the mean of its divisors is an integer number (233190).

2⁹⁰¹⁶³⁹ is an apocalyptic number.

901639 is a deficient number, since it is larger than the sum of its proper divisors (31121).

901639 is a wasteful number, since it uses less digits than its factorization.

901639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31120.

The product of its (nonzero) digits is 1458, while the sum is 28.

The square root of 901639 is about 949.5467339736. The cubic root of 901639 is about 96.6075117003.

It can be divided in two parts, 901 and 639, that added together give a triangular number (1540 = T₅₅).

The spelling of 901639 in words is "nine hundred one thousand, six hundred thirty-nine".