1610991 has 12 divisors (see below), whose sum is σ = 2449720. Its totient is φ = 1017360.

The previous prime is 1610981. The next prime is 1610993. The reversal of 1610991 is 1990161.

It is not a de Polignac number, because 1610991 - 2⁶ = 1610927 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1610993) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4540 + ... + 4881.

2^1610991 is an apocalyptic number.

1610991 is a deficient number, since it is larger than the sum of its proper divisors (838729).

1610991 is a wasteful number, since it uses less digits than its factorization.

1610991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9446 (or 9443 counting only the distinct ones).

The product of its (nonzero) digits is 486, while the sum is 27.

The square root of 1610991 is about 1269.2482026775. The cubic root of 1610991 is about 117.2279142741.

It can be divided in two parts, 1610 and 991, that added together give a square (2601 = 51²).

The spelling of 1610991 in words is "one million, six hundred ten thousand, nine hundred ninety-one".