1378521541 has 4 divisors (see below), whose sum is σ = 1378650784. Its totient is φ = 1378392300.

The previous prime is 1378521511. The next prime is 1378521569. The reversal of 1378521541 is 1451258731.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1451258731 = 13 ⋅111635287.

It is a cyclic number.

It is not a de Polignac number, because 1378521541 - 2⁷ = 1378521413 is a prime.

It is a super-4 number, since 4×1378521541⁴ (a number of 38 digits) contains 4444 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 1378521541.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1378521511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47025 + ... + 70486.

It is an arithmetic number, because the mean of its divisors is an integer number (344662696).

Almost surely, 2^1378521541 is an apocalyptic number.

It is an amenable number.

1378521541 is a deficient number, since it is larger than the sum of its proper divisors (129243).

1378521541 is a wasteful number, since it uses less digits than its factorization.

1378521541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129242.

The product of its digits is 33600, while the sum is 37.

The square root of 1378521541 is about 37128.4465201549. The cubic root of 1378521541 is about 1112.9385495848.

The spelling of 1378521541 in words is "one billion, three hundred seventy-eight million, five hundred twenty-one thousand, five hundred forty-one".