1656993 has 8 divisors (see below), whose sum is σ = 2379328. Its totient is φ = 1019664.

The previous prime is 1656979. The next prime is 1656997. The reversal of 1656993 is 3996561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1656993 - 2¹² = 1652897 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 42487 = 1656993 / (1 + 6 + 5 + 6 + 9 + 9 + 3).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1656997) 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, 21205 + ... + 21282.

It is an arithmetic number, because the mean of its divisors is an integer number (297416).

2^1656993 is an apocalyptic number.

1656993 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1656993 is a deficient number, since it is larger than the sum of its proper divisors (722335).

1656993 is a wasteful number, since it uses less digits than its factorization.

1656993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42503.

The product of its digits is 43740, while the sum is 39.

The square root of 1656993 is about 1287.2424014147. The cubic root of 1656993 is about 118.3332769071. Note that the first 3 decimals are identical.

The spelling of 1656993 in words is "one million, six hundred fifty-six thousand, nine hundred ninety-three".