138897220 has 192 divisors, whose sum is σ = 394813440. Its totient is φ = 39744000.

The previous prime is 138897197. The next prime is 138897257. The reversal of 138897220 is 22798831.

138897220 = T₁₇₃ + T₁₇₄ + ... + T₉₄₂.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1375170 + ... + 1375270.

It is an arithmetic number, because the mean of its divisors is an integer number (2056320).

Almost surely, 2^138897220 is an apocalyptic number.

138897220 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 138897220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (197406720).

138897220 is an abundant number, since it is smaller than the sum of its proper divisors (255916220).

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

138897220 is a wasteful number, since it uses less digits than its factorization.

138897220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194 (or 192 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 138897220 is about 11785.4664735852. The cubic root of 138897220 is about 517.8824387983.

The spelling of 138897220 in words is "one hundred thirty-eight million, eight hundred ninety-seven thousand, two hundred twenty".