1620747 has 12 divisors (see below), whose sum is σ = 2365584. Its totient is φ = 1069200.

The previous prime is 1620743. The next prime is 1620769. The reversal of 1620747 is 7470261.

It is not a de Polignac number, because 1620747 - 2² = 1620743 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 1620747.

It is not an unprimeable number, because it can be changed into a prime (1620743) 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 11 ways as a sum of consecutive naturals, for example, 18 + ... + 1800.

It is an arithmetic number, because the mean of its divisors is an integer number (197132).

2^1620747 is an apocalyptic number.

1620747 is a deficient number, since it is larger than the sum of its proper divisors (744837).

1620747 is a wasteful number, since it uses less digits than its factorization.

1620747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1890 (or 1887 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 1620747 is about 1273.0856216296. The cubic root of 1620747 is about 117.4640783508.

The spelling of 1620747 in words is "one million, six hundred twenty thousand, seven hundred forty-seven".