138407421 has 8 divisors (see below), whose sum is σ = 195398784. Its totient is φ = 86843840.

The previous prime is 138407407. The next prime is 138407453. The reversal of 138407421 is 124704831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138407421 - 2¹³ = 138399229 is a prime.

It is a super-2 number, since 2×138407421² = 38313228375742482, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138407821) 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, 1356885 + ... + 1356986.

It is an arithmetic number, because the mean of its divisors is an integer number (24424848).

Almost surely, 2^138407421 is an apocalyptic number.

It is an amenable number.

138407421 is a deficient number, since it is larger than the sum of its proper divisors (56991363).

138407421 is a wasteful number, since it uses less digits than its factorization.

138407421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2713891.

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 138407421 is about 11764.6683336165. The cubic root of 138407421 is about 517.2729784409.

The spelling of 138407421 in words is "one hundred thirty-eight million, four hundred seven thousand, four hundred twenty-one".