38897407640 has 128 divisors (see below), whose sum is σ = 108259200000. Its totient is φ = 12248299008.

The previous prime is 38897407607. The next prime is 38897407643. The reversal of 38897407640 is 4670479883.

38897407640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×38897407640² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (56).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (38897407643) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 697511 + ... + 751209.

It is an arithmetic number, because the mean of its divisors is an integer number (845775000).

Almost surely, 2^38897407640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 38897407640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54129600000).

38897407640 is an abundant number, since it is smaller than the sum of its proper divisors (69361792360).

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

38897407640 is a wasteful number, since it uses less digits than its factorization.

38897407640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53929 (or 53925 counting only the distinct ones).

The product of its (nonzero) digits is 8128512, while the sum is 56.

The spelling of 38897407640 in words is "thirty-eight billion, eight hundred ninety-seven million, four hundred seven thousand, six hundred forty".