21151752 has 32 divisors (see below), whose sum is σ = 53628480. Its totient is φ = 6950720.

The previous prime is 21151747. The next prime is 21151783. The reversal of 21151752 is 25715112.

It is a super-2 number, since 2×21151752² = 894793225339008, which contains 22 as substring.

It is a hoax number, since the sum of its digits (24) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4503 + ... + 7910.

It is an arithmetic number, because the mean of its divisors is an integer number (1675890).

Almost surely, 2^21151752 is an apocalyptic number.

It is an amenable number.

21151752 is an abundant number, since it is smaller than the sum of its proper divisors (32476728).

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

21151752 is a wasteful number, since it uses less digits than its factorization.

21151752 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12493 (or 12489 counting only the distinct ones).

The product of its digits is 700, while the sum is 24.

The square root of 21151752 is about 4599.1033908796. The cubic root of 21151752 is about 276.5553824144. Note that the first 3 decimals are identical.

Adding to 21151752 its reverse (25715112), we get a palindrome (46866864).

The spelling of 21151752 in words is "twenty-one million, one hundred fifty-one thousand, seven hundred fifty-two".