391616 has 28 divisors (see below), whose sum is σ = 807720. Its totient is φ = 188160.

The previous prime is 391613. The next prime is 391619. The reversal of 391616 is 616193.

391616 = T₄₈ + T₄₉ + ... + T₁₃₄.

It is an interprime number because it is at equal distance from previous prime (391613) and next prime (391619).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391613) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1751 + ... + 1961.

2³⁹¹⁶¹⁶ is an apocalyptic number.

391616 is the 335-th centered heptagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 391616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (403860).

391616 is an abundant number, since it is smaller than the sum of its proper divisors (416104).

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

391616 is a wasteful number, since it uses less digits than its factorization.

391616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252 (or 242 counting only the distinct ones).

The product of its digits is 972, while the sum is 26.

The square root of 391616 is about 625.7922978113. The cubic root of 391616 is about 73.1622088863.

It can be divided in two parts, 3 and 91616, that added together give a palindrome (91619).

The spelling of 391616 in words is "three hundred ninety-one thousand, six hundred sixteen".