1764621997 has 2 divisors, whose sum is σ = 1764621998. Its totient is φ = 1764621996.

The previous prime is 1764621961. The next prime is 1764622043. The reversal of 1764621997 is 7991264671.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 940587561 + 824034436 = 30669^2 + 28706^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1764621997 is a prime.

It is a super-2 number, since 2×1764621997² = 6227781584592536018, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1764625997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 882310998 + 882310999.

It is an arithmetic number, because the mean of its divisors is an integer number (882310999).

Almost surely, 2^1764621997 is an apocalyptic number.

It is an amenable number.

1764621997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1764621997 is an equidigital number, since it uses as much as digits as its factorization.

1764621997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1143072, while the sum is 52.

The square root of 1764621997 is about 42007.4040735678. The cubic root of 1764621997 is about 1208.4181220481.

The spelling of 1764621997 in words is "one billion, seven hundred sixty-four million, six hundred twenty-one thousand, nine hundred ninety-seven".