1249021889 has 2 divisors, whose sum is σ = 1249021890. Its totient is φ = 1249021888.

The previous prime is 1249021861. The next prime is 1249021919. The reversal of 1249021889 is 9881209421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 833188225 + 415833664 = 28865^2 + 20392^2 .

It is a cyclic number.

It is not a de Polignac number, because 1249021889 - 2⁸ = 1249021633 is a prime.

It is a super-2 number, since 2×1249021889² = 3120111358402256642, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1249021819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 624510944 + 624510945.

It is an arithmetic number, because the mean of its divisors is an integer number (624510945).

Almost surely, 2^1249021889 is an apocalyptic number.

It is an amenable number.

1249021889 is a deficient number, since it is larger than the sum of its proper divisors (1).

1249021889 is an equidigital number, since it uses as much as digits as its factorization.

1249021889 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 82944, while the sum is 44.

The square root of 1249021889 is about 35341.5037738917. The cubic root of 1249021889 is about 1076.9363015295.

The spelling of 1249021889 in words is "one billion, two hundred forty-nine million, twenty-one thousand, eight hundred eighty-nine".