11521620 has 162 divisors, whose sum is σ = 40157754. Its totient is φ = 2671680.

The previous prime is 11521607. The next prime is 11521633. The reversal of 11521620 is 2612511.

It is an interprime number because it is at equal distance from previous prime (11521607) and next prime (11521633).

It can be written as a sum of positive squares in only one way, i.e., 9217296 + 2304324 = 3036^2 + 1518^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 11521593 and 11521602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 500929 + ... + 500951.

Almost surely, 2^11521620 is an apocalyptic number.

11521620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 11521620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20078877).

11521620 is an abundant number, since it is smaller than the sum of its proper divisors (28636134).

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

11521620 is a wasteful number, since it uses less digits than its factorization.

11521620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83 (or 44 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 11521620 is about 3394.3511898447. The cubic root of 11521620 is about 225.8592330906.

It can be divided in two parts, 1152 and 1620, that added together give a palindrome (2772).

The spelling of 11521620 in words is "eleven million, five hundred twenty-one thousand, six hundred twenty".