1621247 has 4 divisors (see below), whose sum is σ = 1691760. Its totient is φ = 1550736.

The previous prime is 1621241. The next prime is 1621259. The reversal of 1621247 is 7421261.

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 1621247 - 2⁴ = 1621231 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 70489 = 1621247 / (1 + 6 + 2 + 1 + 2 + 4 + 7).

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621241) 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, 35222 + ... + 35267.

It is an arithmetic number, because the mean of its divisors is an integer number (422940).

2^1621247 is an apocalyptic number.

1621247 is a deficient number, since it is larger than the sum of its proper divisors (70513).

1621247 is an equidigital number, since it uses as much as digits as its factorization.

1621247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70512.

The product of its digits is 672, while the sum is 23.

The square root of 1621247 is about 1273.2819797672. The cubic root of 1621247 is about 117.4761563207.

The spelling of 1621247 in words is "one million, six hundred twenty-one thousand, two hundred forty-seven".