1972721551 has 2 divisors, whose sum is σ = 1972721552. Its totient is φ = 1972721550.

The previous prime is 1972721473. The next prime is 1972721557. The reversal of 1972721551 is 1551272791.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1972721551 - 2²³ = 1964332943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1972721557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 986360775 + 986360776.

It is an arithmetic number, because the mean of its divisors is an integer number (986360776).

Almost surely, 2^1972721551 is an apocalyptic number.

1972721551 is a deficient number, since it is larger than the sum of its proper divisors (1).

1972721551 is an equidigital number, since it uses as much as digits as its factorization.

1972721551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 44100, while the sum is 40.

The square root of 1972721551 is about 44415.3301349883. The cubic root of 1972721551 is about 1254.1666930495.

The spelling of 1972721551 in words is "one billion, nine hundred seventy-two million, seven hundred twenty-one thousand, five hundred fifty-one".