21463688 has 8 divisors (see below), whose sum is σ = 40244430. Its totient is φ = 10731840.

The previous prime is 21463667. The next prime is 21463697. The reversal of 21463688 is 88636412.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 17455684 + 4008004 = 4178^2 + 2002^2 .

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

It is a super-2 number, since 2×21463688² = 921379805122688, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1341473 + ... + 1341488.

Almost surely, 2^21463688 is an apocalyptic number.

It is an amenable number.

21463688 is a deficient number, since it is larger than the sum of its proper divisors (18780742).

21463688 is a wasteful number, since it uses less digits than its factorization.

21463688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2682967 (or 2682963 counting only the distinct ones).

The product of its digits is 55296, while the sum is 38.

The square root of 21463688 is about 4632.8919693859. The cubic root of 21463688 is about 277.9082560471.

The spelling of 21463688 in words is "twenty-one million, four hundred sixty-three thousand, six hundred eighty-eight".