1621387 has 4 divisors (see below), whose sum is σ = 1633896. Its totient is φ = 1608880.

The previous prime is 1621381. The next prime is 1621391. The reversal of 1621387 is 7831261.

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 1621387 - 2⁷ = 1621259 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1621381) 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, 6058 + ... + 6319.

It is an arithmetic number, because the mean of its divisors is an integer number (408474).

2^1621387 is an apocalyptic number.

1621387 is a deficient number, since it is larger than the sum of its proper divisors (12509).

1621387 is a wasteful number, since it uses less digits than its factorization.

1621387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12508.

The product of its digits is 2016, while the sum is 28.

The square root of 1621387 is about 1273.3369546196. The cubic root of 1621387 is about 117.4795377073.

The spelling of 1621387 in words is "one million, six hundred twenty-one thousand, three hundred eighty-seven".