21630070 has 48 divisors (see below), whose sum is σ = 49420368. Its totient is φ = 6740160.

The previous prime is 21630067. The next prime is 21630071. The reversal of 21630070 is 7003612.

21630070 = T₉₁₅ + T₉₁₆ + ... + T₉₆₃.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21630071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3384 + ... + 7396.

It is an arithmetic number, because the mean of its divisors is an integer number (1029591).

Almost surely, 2^21630070 is an apocalyptic number.

21630070 is an abundant number, since it is smaller than the sum of its proper divisors (27790298).

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

21630070 is a wasteful number, since it uses less digits than its factorization.

21630070 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4045 (or 4038 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 19.

The square root of 21630070 is about 4650.8139072640. The cubic root of 21630070 is about 278.6245039599.

Adding to 21630070 its reverse (7003612), we get a palindrome (28633682).

The spelling of 21630070 in words is "twenty-one million, six hundred thirty thousand, seventy".