261506426 has 4 divisors (see below), whose sum is σ = 392259642. Its totient is φ = 130753212.

The previous prime is 261506411. The next prime is 261506429. The reversal of 261506426 is 624605162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 624605162 = 2 ⋅312302581.

It can be written as a sum of positive squares in only one way, i.e., 228040201 + 33466225 = 15101^2 + 5785^2 .

It is a super-2 number, since 2×261506426² = 136771221678586952, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 261506392 and 261506401.

It is not an unprimeable number, because it can be changed into a prime (261506429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65376605 + ... + 65376608.

Almost surely, 2^261506426 is an apocalyptic number.

261506426 is a deficient number, since it is larger than the sum of its proper divisors (130753216).

261506426 is a wasteful number, since it uses less digits than its factorization.

261506426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130753215.

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 261506426 is about 16171.1603170583. The cubic root of 261506426 is about 639.4807197332.

The spelling of 261506426 in words is "two hundred sixty-one million, five hundred six thousand, four hundred twenty-six".