1961512905 has 32 divisors (see below), whose sum is σ = 3436443648. Its totient is φ = 947505600.

The previous prime is 1961512901. The next prime is 1961512907. The reversal of 1961512905 is 5092151691.

It is not a de Polignac number, because 1961512905 - 2² = 1961512901 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1961512901) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22782 + ... + 66648.

It is an arithmetic number, because the mean of its divisors is an integer number (107388864).

Almost surely, 2^1961512905 is an apocalyptic number.

1961512905 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1961512905 is a deficient number, since it is larger than the sum of its proper divisors (1474930743).

1961512905 is a wasteful number, since it uses less digits than its factorization.

1961512905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44157.

The product of its (nonzero) digits is 24300, while the sum is 39.

The square root of 1961512905 is about 44288.9704666975. The cubic root of 1961512905 is about 1251.7868642093.

The spelling of 1961512905 in words is "one billion, nine hundred sixty-one million, five hundred twelve thousand, nine hundred five".