21754137 has 4 divisors (see below), whose sum is σ = 29005520. Its totient is φ = 14502756.

The previous prime is 21754121. The next prime is 21754141. The reversal of 21754137 is 73145712.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21754137 - 2⁴ = 21754121 is a prime.

It is a super-2 number, since 2×21754137² = 946484953229538, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21754637) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 3625687 + ... + 3625692.

It is an arithmetic number, because the mean of its divisors is an integer number (7251380).

Almost surely, 2^21754137 is an apocalyptic number.

It is an amenable number.

21754137 is a deficient number, since it is larger than the sum of its proper divisors (7251383).

21754137 is an equidigital number, since it uses as much as digits as its factorization.

21754137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7251382.

The product of its digits is 5880, while the sum is 30.

The square root of 21754137 is about 4664.1330384113. The cubic root of 21754137 is about 279.1562054841.

Adding to 21754137 its reverse (73145712), we get a palindrome (94899849).

The spelling of 21754137 in words is "twenty-one million, seven hundred fifty-four thousand, one hundred thirty-seven".