1972749761 has 2 divisors, whose sum is σ = 1972749762. Its totient is φ = 1972749760.

The previous prime is 1972749749. The next prime is 1972749763. The reversal of 1972749761 is 1679472791.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1493358736 + 479391025 = 38644^2 + 21895^2 .

It is a cyclic number.

It is not a de Polignac number, because 1972749761 - 2¹⁸ = 1972487617 is a prime.

Together with 1972749763, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1972749763) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 986374880 + 986374881.

It is an arithmetic number, because the mean of its divisors is an integer number (986374881).

Almost surely, 2^1972749761 is an apocalyptic number.

It is an amenable number.

1972749761 is a deficient number, since it is larger than the sum of its proper divisors (1).

1972749761 is an equidigital number, since it uses as much as digits as its factorization.

1972749761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1333584, while the sum is 53.

The square root of 1972749761 is about 44415.6477043845. The cubic root of 1972749761 is about 1254.1726712329.

The spelling of 1972749761 in words is "one billion, nine hundred seventy-two million, seven hundred forty-nine thousand, seven hundred sixty-one".