1331621541 has 6 divisors (see below), whose sum is σ = 1923453350. Its totient is φ = 887747688.

The previous prime is 1331621537. The next prime is 1331621561. The reversal of 1331621541 is 1451261331.

It is a happy number.

1331621541 is a `hidden beast` number, since 1 + 3 + 31 + 621 + 5 + 4 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1305304641 + 26316900 = 36129^2 + 5130^2 .

It is not a de Polignac number, because 1331621541 - 2² = 1331621537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1331621561) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 73978966 + ... + 73978983.

Almost surely, 2^1331621541 is an apocalyptic number.

It is an amenable number.

1331621541 is a deficient number, since it is larger than the sum of its proper divisors (591831809).

1331621541 is a wasteful number, since it uses less digits than its factorization.

1331621541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147957955 (or 147957952 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 1331621541 is about 36491.3899570844. The cubic root of 1331621541 is about 1100.1711967707.

Adding to 1331621541 its reverse (1451261331), we get a palindrome (2782882872).

The spelling of 1331621541 in words is "one billion, three hundred thirty-one million, six hundred twenty-one thousand, five hundred forty-one".