20919570 has 128 divisors (see below), whose sum is σ = 62208000. Its totient is φ = 4487616.

The previous prime is 20919557. The next prime is 20919593. The reversal of 20919570 is 7591902.

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 63 ways as a sum of consecutive naturals, for example, 195457 + ... + 195563.

It is an arithmetic number, because the mean of its divisors is an integer number (486000).

Almost surely, 2^20919570 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20919570, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31104000).

20919570 is an abundant number, since it is smaller than the sum of its proper divisors (41288430).

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

20919570 is a wasteful number, since it uses less digits than its factorization.

20919570 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157 (or 143 counting only the distinct ones).

The product of its (nonzero) digits is 5670, while the sum is 33.

The square root of 20919570 is about 4573.7916437022. The cubic root of 20919570 is about 275.5397443548.

The spelling of 20919570 in words is "twenty million, nine hundred nineteen thousand, five hundred seventy".