3639156421 has 2 divisors, whose sum is σ = 3639156422. Its totient is φ = 3639156420.

The previous prime is 3639156413. The next prime is 3639156461. The reversal of 3639156421 is 1246519363.

3639156421 = T₄₉₂₅₄ + T₄₉₂₅₅ + T₄₉₂₅₆.

It is an a-pointer prime, because the next prime (3639156461) can be obtained adding 3639156421 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3630665025 + 8491396 = 60255^2 + 2914^2 .

It is an emirp because it is prime and its reverse (1246519363) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3639156421 - 2³ = 3639156413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3639156461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1819578210 + 1819578211.

It is an arithmetic number, because the mean of its divisors is an integer number (1819578211).

Almost surely, 2^3639156421 is an apocalyptic number.

3639156421 is the 49256-th centered triangular number.

It is an amenable number.

3639156421 is a deficient number, since it is larger than the sum of its proper divisors (1).

3639156421 is an equidigital number, since it uses as much as digits as its factorization.

3639156421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 116640, while the sum is 40.

The square root of 3639156421 is about 60325.4210180087. The cubic root of 3639156421 is about 1538.1554940548.

The spelling of 3639156421 in words is "three billion, six hundred thirty-nine million, one hundred fifty-six thousand, four hundred twenty-one".