20897188770 has 32 divisors (see below), whose sum is σ = 50157377280. Its totient is φ = 5572125440.

The previous prime is 20897188757. The next prime is 20897188777. The reversal of 20897188770 is 7788179802.

It is a super-2 number, since 2×20897188770² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20897188770.

It is not an unprimeable number, because it can be changed into a prime (20897188777) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 505690 + ... + 545450.

It is an arithmetic number, because the mean of its divisors is an integer number (1567418040).

Almost surely, 2^20897188770 is an apocalyptic number.

20897188770 is an abundant number, since it is smaller than the sum of its proper divisors (29260188510).

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

20897188770 is a wasteful number, since it uses less digits than its factorization.

20897188770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57290.

The product of its (nonzero) digits is 3161088, while the sum is 57.

The spelling of 20897188770 in words is "twenty billion, eight hundred ninety-seven million, one hundred eighty-eight thousand, seven hundred seventy".