20451644 has 12 divisors (see below), whose sum is σ = 36107904. Its totient is φ = 10135104.

The previous prime is 20451643. The next prime is 20451647. The reversal of 20451644 is 44615402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20451643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22172 + ... + 23075.

It is an arithmetic number, because the mean of its divisors is an integer number (3008992).

Almost surely, 2^20451644 is an apocalyptic number.

It is an amenable number.

20451644 is a deficient number, since it is larger than the sum of its proper divisors (15656260).

20451644 is a wasteful number, since it uses less digits than its factorization.

20451644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45364 (or 45362 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 26.

The square root of 20451644 is about 4522.3493894214. The cubic root of 20451644 is about 273.4698221100.

The spelling of 20451644 in words is "twenty million, four hundred fifty-one thousand, six hundred forty-four".