1945604261 has 4 divisors (see below), whose sum is σ = 1945742400. Its totient is φ = 1945466124.

The previous prime is 1945604257. The next prime is 1945604371. The reversal of 1945604261 is 1624065491.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1624065491 = 13049 ⋅124459.

It is a cyclic number.

It is not a de Polignac number, because 1945604261 - 2² = 1945604257 is a prime.

It is a super-2 number, since 2×1945604261² = 7570751880842712242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1945604561) 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, 45191 + ... + 77028.

It is an arithmetic number, because the mean of its divisors is an integer number (486435600).

Almost surely, 2^1945604261 is an apocalyptic number.

It is an amenable number.

1945604261 is a deficient number, since it is larger than the sum of its proper divisors (138139).

1945604261 is a wasteful number, since it uses less digits than its factorization.

1945604261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138138.

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 1945604261 is about 44109.0043075107. The cubic root of 1945604261 is about 1248.3935119213.

The spelling of 1945604261 in words is "one billion, nine hundred forty-five million, six hundred four thousand, two hundred sixty-one".