21471630 has 32 divisors (see below), whose sum is σ = 51655968. Its totient is φ = 5712000.

The previous prime is 21471589. The next prime is 21471631. The reversal of 21471630 is 3617412.

It is a super-2 number, since 2×21471630² = 922061789713800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21471630.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21471631) 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, 20520 + ... + 21540.

It is an arithmetic number, because the mean of its divisors is an integer number (1614249).

Almost surely, 2^21471630 is an apocalyptic number.

21471630 is an abundant number, since it is smaller than the sum of its proper divisors (30184338).

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

21471630 is a wasteful number, since it uses less digits than its factorization.

21471630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1732.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21471630 is about 4633.7490221202. The cubic root of 21471630 is about 277.9425290511.

The spelling of 21471630 in words is "twenty-one million, four hundred seventy-one thousand, six hundred thirty".