1262632021561 has 3 divisors (see below), whose sum is σ = 1262633145231. Its totient is φ = 1262630897892.

The previous prime is 1262632021549. The next prime is 1262632021597. The reversal of 1262632021561 is 1651202362621.

The square root of 1262632021561 is 1123669.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1063412625961 + 199219395600 = 1031219^2 + 446340^2 .

It is not a de Polignac number, because 1262632021561 - 2¹¹ = 1262632019513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1262632021561.

It is not an unprimeable number, because it can be changed into a prime (1262632021961) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 561835 + ... + 1685503.

It is an arithmetic number, because the mean of its divisors is an integer number (420877715077).

Almost surely, 2^{1262632021561} is an apocalyptic number.

1262632021561 is the 1123669-th square number.

1262632021561 is the 561835-th centered octagonal number.

It is an amenable number.

1262632021561 is a deficient number, since it is larger than the sum of its proper divisors (1123670).

1262632021561 is an frugal number, since it uses more digits than its factorization.

1262632021561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2247338 (or 1123669 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 37.

The spelling of 1262632021561 in words is "one trillion, two hundred sixty-two billion, six hundred thirty-two million, twenty-one thousand, five hundred sixty-one".