1972138577 has 4 divisors (see below), whose sum is σ = 1976631360. Its totient is φ = 1967645796.

The previous prime is 1972138549. The next prime is 1972138589. The reversal of 1972138577 is 7758312791.

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.

It is a cyclic number.

It is not a de Polignac number, because 1972138577 - 2¹⁶ = 1972073041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1972138537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2245733 + ... + 2246610.

It is an arithmetic number, because the mean of its divisors is an integer number (494157840).

Almost surely, 2^1972138577 is an apocalyptic number.

It is an amenable number.

1972138577 is a deficient number, since it is larger than the sum of its proper divisors (4492783).

1972138577 is an equidigital number, since it uses as much as digits as its factorization.

1972138577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4492782.

The product of its digits is 740880, while the sum is 50.

The square root of 1972138577 is about 44408.7668934862. The cubic root of 1972138577 is about 1254.0431380877.

The spelling of 1972138577 in words is "one billion, nine hundred seventy-two million, one hundred thirty-eight thousand, five hundred seventy-seven".