21151650 has 48 divisors (see below), whose sum is σ = 56496384. Its totient is φ = 5206080.

The previous prime is 21151639. The next prime is 21151661. The reversal of 21151650 is 5615112.

It is an interprime number because it is at equal distance from previous prime (21151639) and next prime (21151661).

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3474 + ... + 7373.

It is an arithmetic number, because the mean of its divisors is an integer number (1177008).

Almost surely, 2^21151650 is an apocalyptic number.

21151650 is an abundant number, since it is smaller than the sum of its proper divisors (35344734).

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

21151650 is a wasteful number, since it uses less digits than its factorization.

21151650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10875 (or 10870 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 21.

The square root of 21151650 is about 4599.0923017482. The cubic root of 21151650 is about 276.5549378698.

Adding to 21151650 its reverse (5615112), we get a palindrome (26766762).

The spelling of 21151650 in words is "twenty-one million, one hundred fifty-one thousand, six hundred fifty".