1013212561 has 9 divisors (see below), whose sum is σ = 1025030331. Its totient is φ = 1001530584.

The previous prime is 1013212549. The next prime is 1013212573. The reversal of 1013212561 is 1652123101.

It is a happy number.

The square root of 1013212561 is 31831.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (1013212549) and next prime (1013212573).

It can be written as a sum of positive squares in only one way, i.e., 943656961 + 69555600 = 30719^2 + 8340^2 .

It is not a de Polignac number, because 1013212561 - 2¹⁵ = 1013179793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1013212061) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4424395 + ... + 4424623.

It is an arithmetic number, because the mean of its divisors is an integer number (113892259).

Almost surely, 2^1013212561 is an apocalyptic number.

1013212561 is the 31831-st square number.

1013212561 is the 15916-th centered octagonal number.

It is an amenable number.

1013212561 is a deficient number, since it is larger than the sum of its proper divisors (11817770).

1013212561 is an frugal number, since it uses more digits than its factorization.

1013212561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 736 (or 368 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 22.

The cubic root of 1013212561 is about 1004.3849312738.

Adding to 1013212561 its reverse (1652123101), we get a palindrome (2665335662).

The spelling of 1013212561 in words is "one billion, thirteen million, two hundred twelve thousand, five hundred sixty-one".