1264544921 has 2 divisors, whose sum is σ = 1264544922. Its totient is φ = 1264544920.

The previous prime is 1264544857. The next prime is 1264544927. The reversal of 1264544921 is 1294454621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1191630400 + 72914521 = 34520^2 + 8539^2 .

It is a cyclic number.

It is not a de Polignac number, because 1264544921 - 2⁶ = 1264544857 is a prime.

It is not a weakly prime, because it can be changed into another prime (1264544927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 632272460 + 632272461.

It is an arithmetic number, because the mean of its divisors is an integer number (632272461).

Almost surely, 2^1264544921 is an apocalyptic number.

It is an amenable number.

1264544921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1264544921 is an equidigital number, since it uses as much as digits as its factorization.

1264544921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69120, while the sum is 38.

The square root of 1264544921 is about 35560.4403937859. The cubic root of 1264544921 is about 1081.3793877438.

The spelling of 1264544921 in words is "one billion, two hundred sixty-four million, five hundred forty-four thousand, nine hundred twenty-one".