20901189690 has 24 divisors (see below), whose sum is σ = 54343093428. Its totient is φ = 5573650560.

The previous prime is 20901189689. The next prime is 20901189731. The reversal of 20901189690 is 9698110902.

It can be written as a sum of positive squares in 2 ways, for example, as 16843627089 + 4057562601 = 129783^2 + 63699^2 .

It is a super-2 number, since 2×20901189690² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 116117631 + ... + 116117810.

Almost surely, 2^20901189690 is an apocalyptic number.

20901189690 is an abundant number, since it is smaller than the sum of its proper divisors (33441903738).

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

20901189690 is a wasteful number, since it uses less digits than its factorization.

20901189690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232235454 (or 232235451 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 45.

The spelling of 20901189690 in words is "twenty billion, nine hundred one million, one hundred eighty-nine thousand, six hundred ninety".