21247496 has 8 divisors (see below), whose sum is σ = 39839070. Its totient is φ = 10623744.

The previous prime is 21247487. The next prime is 21247519. The reversal of 21247496 is 69474212.

It can be written as a sum of positive squares in only one way, i.e., 17522596 + 3724900 = 4186^2 + 1930^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1327961 + ... + 1327976.

Almost surely, 2^21247496 is an apocalyptic number.

It is an amenable number.

21247496 is a deficient number, since it is larger than the sum of its proper divisors (18591574).

21247496 is a wasteful number, since it uses less digits than its factorization.

21247496 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2655943 (or 2655939 counting only the distinct ones).

The product of its digits is 24192, while the sum is 35.

The square root of 21247496 is about 4609.5006237119. The cubic root of 21247496 is about 276.9720329560.

The spelling of 21247496 in words is "twenty-one million, two hundred forty-seven thousand, four hundred ninety-six".