1621797 has 4 divisors (see below), whose sum is σ = 2162400. Its totient is φ = 1081196.

The previous prime is 1621793. The next prime is 1621819. The reversal of 1621797 is 7971261.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1621797 - 2² = 1621793 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621793) 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, 270297 + ... + 270302.

It is an arithmetic number, because the mean of its divisors is an integer number (540600).

2^1621797 is an apocalyptic number.

It is an amenable number.

1621797 is a deficient number, since it is larger than the sum of its proper divisors (540603).

1621797 is an equidigital number, since it uses as much as digits as its factorization.

1621797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540602.

The product of its digits is 5292, while the sum is 33.

The square root of 1621797 is about 1273.4979387498. The cubic root of 1621797 is about 117.4894392198.

The spelling of 1621797 in words is "one million, six hundred twenty-one thousand, seven hundred ninety-seven".