21542722 has 4 divisors (see below), whose sum is σ = 32314086. Its totient is φ = 10771360.

The previous prime is 21542687. The next prime is 21542761. The reversal of 21542722 is 22724512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 11296321 + 10246401 = 3361^2 + 3201^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 5385679 + ... + 5385682.

Almost surely, 2^21542722 is an apocalyptic number.

21542722 is a deficient number, since it is larger than the sum of its proper divisors (10771364).

21542722 is a wasteful number, since it uses less digits than its factorization.

21542722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10771363.

The product of its digits is 2240, while the sum is 25.

The square root of 21542722 is about 4641.4137932315. The cubic root of 21542722 is about 278.2489445800.

The spelling of 21542722 in words is "twenty-one million, five hundred forty-two thousand, seven hundred twenty-two".