1377212521 has 4 divisors (see below), whose sum is σ = 1378379844. Its totient is φ = 1376045200.

The previous prime is 1377212519. The next prime is 1377212531. The reversal of 1377212521 is 1252127731.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1252127731 = 4357 ⋅287383.

It can be written as a sum of positive squares in 2 ways, for example, as 1201384921 + 175827600 = 34661^2 + 13260^2 .

It is a cyclic number.

It is not a de Polignac number, because 1377212521 - 2¹ = 1377212519 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1377212531) 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, 581890 + ... + 584251.

It is an arithmetic number, because the mean of its divisors is an integer number (344594961).

Almost surely, 2^1377212521 is an apocalyptic number.

It is an amenable number.

1377212521 is a deficient number, since it is larger than the sum of its proper divisors (1167323).

1377212521 is a wasteful number, since it uses less digits than its factorization.

1377212521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1167322.

The product of its digits is 5880, while the sum is 31.

The square root of 1377212521 is about 37110.8140708339. The cubic root of 1377212521 is about 1112.5861623457.

The spelling of 1377212521 in words is "one billion, three hundred seventy-seven million, two hundred twelve thousand, five hundred twenty-one".