1013591981 has 8 divisors (see below), whose sum is σ = 1042196760. Its totient is φ = 985338432.

The previous prime is 1013591939. The next prime is 1013591987. The reversal of 1013591981 is 1891953101.

It can be written as a sum of positive squares in 4 ways, for example, as 657666025 + 355925956 = 25645^2 + 18866^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1013591981 - 2¹⁰ = 1013590957 is a prime.

It is a super-2 number, since 2×1013591981² = 2054737407895008722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1013591987) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81950 + ... + 93503.

It is an arithmetic number, because the mean of its divisors is an integer number (130274595).

Almost surely, 2^1013591981 is an apocalyptic number.

It is an amenable number.

1013591981 is a deficient number, since it is larger than the sum of its proper divisors (28604779).

1013591981 is a wasteful number, since it uses less digits than its factorization.

1013591981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175615.

The product of its (nonzero) digits is 9720, while the sum is 38.

The square root of 1013591981 is about 31836.9593554410. The cubic root of 1013591981 is about 1004.5102870602.

The spelling of 1013591981 in words is "one billion, thirteen million, five hundred ninety-one thousand, nine hundred eighty-one".