21150774 has 32 divisors (see below), whose sum is σ = 47779680. Its totient is φ = 6933600.

The previous prime is 21150757. The next prime is 21150803. The reversal of 21150774 is 47705112.

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

It is a Curzon number.

It is a congruent number.

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, 84 + ... + 6504.

It is an arithmetic number, because the mean of its divisors is an integer number (1493115).

Almost surely, 2^21150774 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21150774, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23889840).

21150774 is an abundant number, since it is smaller than the sum of its proper divisors (26628906).

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

21150774 is a wasteful number, since it uses less digits than its factorization.

21150774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6493 (or 6487 counting only the distinct ones).

The product of its (nonzero) digits is 1960, while the sum is 27.

The square root of 21150774 is about 4598.9970645783. The cubic root of 21150774 is about 276.5511199569.

Adding to 21150774 its sum of digits (27), we get a square (21150801 = 4599²).

Adding to 21150774 its reverse (47705112), we get a palindrome (68855886).

The spelling of 21150774 in words is "twenty-one million, one hundred fifty thousand, seven hundred seventy-four".