20475780 has 48 divisors (see below), whose sum is σ = 61744704. Its totient is φ = 5040000.

The previous prime is 20475743. The next prime is 20475799. The reversal of 20475780 is 8757402.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12346 + ... + 13905.

It is an arithmetic number, because the mean of its divisors is an integer number (1286348).

Almost surely, 2^20475780 is an apocalyptic number.

20475780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20475780 is an abundant number, since it is smaller than the sum of its proper divisors (41268924).

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

20475780 is a wasteful number, since it uses less digits than its factorization.

20475780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26276 (or 26274 counting only the distinct ones).

The product of its (nonzero) digits is 15680, while the sum is 33.

The square root of 20475780 is about 4525.0171270394. The cubic root of 20475780 is about 273.5773582542.

It can be divided in two parts, 20 and 475780, that added together give a triangular number (475800 = T₉₇₅).

The spelling of 20475780 in words is "twenty million, four hundred seventy-five thousand, seven hundred eighty".