1387553421 has 8 divisors (see below), whose sum is σ = 1860293344. Its totient is φ = 919924560.

The previous prime is 1387553417. The next prime is 1387553449. The reversal of 1387553421 is 1243557831.

It is a happy number.

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

It is not a de Polignac number, because 1387553421 - 2² = 1387553417 is a prime.

It is a super-2 number, since 2×1387553421² = 3850608992257606482, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1387553421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1187553421) 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, 1277131 + ... + 1278216.

It is an arithmetic number, because the mean of its divisors is an integer number (232536668).

Almost surely, 2^1387553421 is an apocalyptic number.

It is an amenable number.

1387553421 is a deficient number, since it is larger than the sum of its proper divisors (472739923).

1387553421 is a wasteful number, since it uses less digits than its factorization.

1387553421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2555531.

The product of its digits is 100800, while the sum is 39.

The square root of 1387553421 is about 37249.8781340288. The cubic root of 1387553421 is about 1115.3638663096.

The spelling of 1387553421 in words is "one billion, three hundred eighty-seven million, five hundred fifty-three thousand, four hundred twenty-one".