1661958 has 20 divisors (see below), whose sum is σ = 3724380. Its totient is φ = 553932.

The previous prime is 1661953. The next prime is 1661969. The reversal of 1661958 is 8591661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661953) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 4968 + ... + 5291.

It is an arithmetic number, because the mean of its divisors is an integer number (186219).

2^1661958 is an apocalyptic number.

1661958 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1661958 is an abundant number, since it is smaller than the sum of its proper divisors (2062422).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1661958 is a wasteful number, since it uses less digits than its factorization.

1661958 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10273 (or 10264 counting only the distinct ones).

The product of its digits is 12960, while the sum is 36.

The square root of 1661958 is about 1289.1695001046. The cubic root of 1661958 is about 118.4513500023.

The spelling of 1661958 in words is "one million, six hundred sixty-one thousand, nine hundred fifty-eight".