20781148 has 12 divisors (see below), whose sum is σ = 36599752. Its totient is φ = 10324080.

The previous prime is 20781133. The next prime is 20781149. The reversal of 20781148 is 84118702.

It is a super-2 number, since 2×20781148² = 863712224395808, which contains 22 as substring.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20781149) 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, 15918 + ... + 17173.

Almost surely, 2^20781148 is an apocalyptic number.

It is an amenable number.

20781148 is a deficient number, since it is larger than the sum of its proper divisors (15818604).

20781148 is a wasteful number, since it uses less digits than its factorization.

20781148 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33252 (or 33250 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 20781148 is about 4558.6344446555. The cubic root of 20781148 is about 274.9306624087.

The spelling of 20781148 in words is "twenty million, seven hundred eighty-one thousand, one hundred forty-eight".