20399648 has 12 divisors (see below), whose sum is σ = 40161870. Its totient is φ = 10199808.

The previous prime is 20399633. The next prime is 20399651. The reversal of 20399648 is 84699302.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 14961424 + 5438224 = 3868^2 + 2332^2 .

It is a super-2 number, since 2×20399648² = 832291277047808, 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, 318713 + ... + 318776.

Almost surely, 2^20399648 is an apocalyptic number.

It is an amenable number.

20399648 is a deficient number, since it is larger than the sum of its proper divisors (19762222).

20399648 is an equidigital number, since it uses as much as digits as its factorization.

20399648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637499 (or 637491 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 41.

The square root of 20399648 is about 4516.5969490314. The cubic root of 20399648 is about 273.2378700271.

The spelling of 20399648 in words is "twenty million, three hundred ninety-nine thousand, six hundred forty-eight".