261715890426 has 128 divisors (see below), whose sum is σ = 564354895104. Its totient is φ = 80625807360.

The previous prime is 261715890421. The next prime is 261715890427. The reversal of 261715890426 is 624098517162.

It is a super-2 number, since 2×261715890426² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is not an unprimeable number, because it can be changed into a prime (261715890421) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 825602020 + ... + 825602336.

It is an arithmetic number, because the mean of its divisors is an integer number (4409022618).

Almost surely, 2^261715890426 is an apocalyptic number.

261715890426 is an abundant number, since it is smaller than the sum of its proper divisors (302639004678).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261715890426 is a wasteful number, since it uses less digits than its factorization.

261715890426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 944.

The product of its (nonzero) digits is 1451520, while the sum is 51.

The spelling of 261715890426 in words is "two hundred sixty-one billion, seven hundred fifteen million, eight hundred ninety thousand, four hundred twenty-six".