21127554 has 80 divisors (see below), whose sum is σ = 55942656. Its totient is φ = 5832000.

The previous prime is 21127537. The next prime is 21127591. The reversal of 21127554 is 45572112.

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

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 34854 + ... + 35454.

Almost surely, 2^21127554 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21127554, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27971328).

21127554 is an abundant number, since it is smaller than the sum of its proper divisors (34815102).

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

21127554 is a wasteful number, since it uses less digits than its factorization.

21127554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 653 (or 644 counting only the distinct ones).

The product of its digits is 2800, while the sum is 27.

The square root of 21127554 is about 4596.4719078876. The cubic root of 21127554 is about 276.4498806617.

Adding to 21127554 its reverse (45572112), we get a palindrome (66699666).

The spelling of 21127554 in words is "twenty-one million, one hundred twenty-seven thousand, five hundred fifty-four".