21277152 has 72 divisors (see below), whose sum is σ = 65172744. Its totient is φ = 6545664.

The previous prime is 21277121. The next prime is 21277153. The reversal of 21277152 is 25177212.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×21277152² = 905434394462208, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21277153) 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, 903 + ... + 6585.

It is an arithmetic number, because the mean of its divisors is an integer number (905177).

Almost surely, 2^21277152 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 21277152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32586372).

21277152 is an abundant number, since it is smaller than the sum of its proper divisors (43895592).

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

21277152 is a wasteful number, since it uses less digits than its factorization.

21277152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5712 (or 5701 counting only the distinct ones).

The product of its digits is 1960, while the sum is 27.

The square root of 21277152 is about 4612.7163363901. The cubic root of 21277152 is about 277.1008334523.

The spelling of 21277152 in words is "twenty-one million, two hundred seventy-seven thousand, one hundred fifty-two".