21125130 has 32 divisors (see below), whose sum is σ = 54601344. Its totient is φ = 5199936.

The previous prime is 21125123. The next prime is 21125161. The reversal of 21125130 is 3152112.

It is a super-2 number, since 2×21125130² = 892542235033800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26694 + ... + 27473.

It is an arithmetic number, because the mean of its divisors is an integer number (1706292).

Almost surely, 2^21125130 is an apocalyptic number.

21125130 is an abundant number, since it is smaller than the sum of its proper divisors (33476214).

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

21125130 is a wasteful number, since it uses less digits than its factorization.

21125130 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54190.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 21125130 is about 4596.2082198264. The cubic root of 21125130 is about 276.4393077366.

Adding to 21125130 its reverse (3152112), we get a palindrome (24277242).

The spelling of 21125130 in words is "twenty-one million, one hundred twenty-five thousand, one hundred thirty".