20700437638 has 16 divisors (see below), whose sum is σ = 31386429504. Its totient is φ = 10238576040.

The previous prime is 20700437633. The next prime is 20700437663. The reversal of 20700437638 is 83673400702.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20700437638.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20700437633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77881 + ... + 217867.

It is an arithmetic number, because the mean of its divisors is an integer number (1961651844).

Almost surely, 2^20700437638 is an apocalyptic number.

20700437638 is a deficient number, since it is larger than the sum of its proper divisors (10685991866).

20700437638 is a wasteful number, since it uses less digits than its factorization.

20700437638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140787.

The product of its (nonzero) digits is 169344, while the sum is 40.

The spelling of 20700437638 in words is "twenty billion, seven hundred million, four hundred thirty-seven thousand, six hundred thirty-eight".