261420634 has 4 divisors (see below), whose sum is σ = 392130954. Its totient is φ = 130710316.

The previous prime is 261420629. The next prime is 261420637. The reversal of 261420634 is 436024162.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 236390625 + 25030009 = 15375^2 + 5003^2 .

It is not an unprimeable number, because it can be changed into a prime (261420637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65355157 + ... + 65355160.

Almost surely, 2^261420634 is an apocalyptic number.

261420634 is a deficient number, since it is larger than the sum of its proper divisors (130710320).

261420634 is a wasteful number, since it uses less digits than its factorization.

261420634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130710319.

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 261420634 is about 16168.5074759546. The cubic root of 261420634 is about 639.4107809413.

Adding to 261420634 its reverse (436024162), we get a palindrome (697444796).

The spelling of 261420634 in words is "two hundred sixty-one million, four hundred twenty thousand, six hundred thirty-four".