33121620 has 144 divisors (see below), whose sum is σ = 116433408. Its totient is φ = 7464960.

The previous prime is 33121591. The next prime is 33121639. The reversal of 33121620 is 2612133.

33121620 is a `hidden beast` number, since 33 + 12 + 1 + 620 = 666.

It is a super-2 number, since 2×33121620² = 2194083422848800, which contains 22 as substring.

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 = 33121593 and 33121602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 122085 + ... + 122355.

Almost surely, 2^33121620 is an apocalyptic number.

33121620 is a gapful number since it is divisible by the number (30) 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 33121620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (58216704).

33121620 is an abundant number, since it is smaller than the sum of its proper divisors (83311788).

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

33121620 is a wasteful number, since it uses less digits than its factorization.

33121620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 390 (or 385 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

The square root of 33121620 is about 5755.1385734837. The cubic root of 33121620 is about 321.1469906478.

Adding to 33121620 its reverse (2612133), we get a palindrome (35733753).

The spelling of 33121620 in words is "thirty-three million, one hundred twenty-one thousand, six hundred twenty".