21097152 has 112 divisors (see below), whose sum is σ = 64312800. Its totient is φ = 6773760.

The previous prime is 21097129. The next prime is 21097159. The reversal of 21097152 is 25179012.

It is a super-2 number, since 2×21097152² = 890179645022208, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21097159) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49902 + ... + 50322.

Almost surely, 2^21097152 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21097152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32156400).

21097152 is an abundant number, since it is smaller than the sum of its proper divisors (43215648).

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

21097152 is a wasteful number, since it uses less digits than its factorization.

21097152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 471 (or 455 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 27.

The square root of 21097152 is about 4593.1636156357. The cubic root of 21097152 is about 276.3172156146.

It can be divided in two parts, 2109 and 7152, that added together give a cube (9261 = 21³).

The spelling of 21097152 in words is "twenty-one million, ninety-seven thousand, one hundred fifty-two".