1621646 has 16 divisors (see below), whose sum is σ = 2650704. Its totient is φ = 739584.

The previous prime is 1621643. The next prime is 1621657. The reversal of 1621646 is 6461261.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2201 + ... + 2843.

It is an arithmetic number, because the mean of its divisors is an integer number (165669).

2^1621646 is an apocalyptic number.

1621646 is a deficient number, since it is larger than the sum of its proper divisors (1029058).

1621646 is a wasteful number, since it uses less digits than its factorization.

1621646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 755.

The product of its digits is 1728, while the sum is 26.

The square root of 1621646 is about 1273.4386518400. The cubic root of 1621646 is about 117.4857927594.

The spelling of 1621646 in words is "one million, six hundred twenty-one thousand, six hundred forty-six".