It is a self number, because there is not a number n which added to its sum of digits gives 137021640.
It is an unprimeable number.
Almost surely, 2137021640 is an apocalyptic number.
137021640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 137021640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (239760000).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
137021640 is a wasteful number, since it uses less digits than its factorization.
137021640 is an evil number, because the sum of its binary digits is even.
The square root of 137021640 is about 11705.6242892039. The cubic root of 137021640 is about 515.5408149796.
Subtracting from 137021640 its reverse (46120731), we obtain a palindrome (90900909).
The spelling of 137021640 in words is "one hundred thirty-seven million, twenty-one thousand, six hundred forty".