1015021981 has 2 divisors, whose sum is σ = 1015021982. Its totient is φ = 1015021980.

The previous prime is 1015021961. The next prime is 1015022033. The reversal of 1015021981 is 1891205101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 541306756 + 473715225 = 23266^2 + 21765^2 .

It is a cyclic number.

It is not a de Polignac number, because 1015021981 - 2⁷ = 1015021853 is a prime.

It is a super-2 number, since 2×1015021981² = 2060539243826328722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1015021961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 507510990 + 507510991.

It is an arithmetic number, because the mean of its divisors is an integer number (507510991).

Almost surely, 2^1015021981 is an apocalyptic number.

It is an amenable number.

1015021981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1015021981 is an equidigital number, since it uses as much as digits as its factorization.

1015021981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 28.

The square root of 1015021981 is about 31859.4096147433. The cubic root of 1015021981 is about 1004.9824608541.

It can be divided in two parts, 10150 and 21981, that added together give a triangular number (32131 = T₂₅₃).

The spelling of 1015021981 in words is "one billion, fifteen million, twenty-one thousand, nine hundred eighty-one".