261421124537437 has 4 divisors (see below), whose sum is σ = 262789821524736. Its totient is φ = 260052427550140.

The previous prime is 261421124537431. The next prime is 261421124537491. The reversal of 261421124537437 is 734735421124162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 261421124537437 - 2³ = 261421124537429 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261421124537431) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 684348493363 + ... + 684348493744.

It is an arithmetic number, because the mean of its divisors is an integer number (65697455381184).

Almost surely, 2^{261421124537437} is an apocalyptic number.

It is an amenable number.

261421124537437 is a deficient number, since it is larger than the sum of its proper divisors (1368696987299).

261421124537437 is a wasteful number, since it uses less digits than its factorization.

261421124537437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1368696987298.

The product of its digits is 6773760, while the sum is 52.

The spelling of 261421124537437 in words is "two hundred sixty-one trillion, four hundred twenty-one billion, one hundred twenty-four million, five hundred thirty-seven thousand, four hundred thirty-seven".