20401810 has 48 divisors (see below), whose sum is σ = 43503768. Its totient is φ = 6842880.

The previous prime is 20401793. The next prime is 20401831. The reversal of 20401810 is 1810402.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 18688329 + 1713481 = 4323^2 + 1309^2 .

It is a super-2 number, since 2×20401810² = 832467702552200, which contains 22 as substring.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 15082 + ... + 16378.

Almost surely, 2^20401810 is an apocalyptic number.

20401810 is an abundant number, since it is smaller than the sum of its proper divisors (23101958).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20401810 is a wasteful number, since it uses less digits than its factorization.

20401810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1339 (or 1328 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 20401810 is about 4516.8362821780. The cubic root of 20401810 is about 273.2475224716.

The spelling of 20401810 in words is "twenty million, four hundred one thousand, eight hundred ten".