1621139 has 4 divisors (see below), whose sum is σ = 1745856. Its totient is φ = 1496424.

The previous prime is 1621133. The next prime is 1621141. The reversal of 1621139 is 9311261.

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: 9311261 = 1933 ⋅4817.

It is a cyclic number.

It is not a de Polignac number, because 1621139 - 2¹² = 1617043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1621133) 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, 62339 + ... + 62364.

It is an arithmetic number, because the mean of its divisors is an integer number (436464).

2^1621139 is an apocalyptic number.

1621139 is a deficient number, since it is larger than the sum of its proper divisors (124717).

1621139 is a wasteful number, since it uses less digits than its factorization.

1621139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124716.

The product of its digits is 324, while the sum is 23.

The square root of 1621139 is about 1273.2395689736. The cubic root of 1621139 is about 117.4735476895.

The spelling of 1621139 in words is "one million, six hundred twenty-one thousand, one hundred thirty-nine".