1864647961 has 16 divisors (see below), whose sum is σ = 2093128128. Its totient is φ = 1646632000.

The previous prime is 1864647949. The next prime is 1864647971. The reversal of 1864647961 is 1697464681.

It is a cyclic number.

It is not a de Polignac number, because 1864647961 - 2²⁹ = 1327777049 is a prime.

It is a super-2 number, since 2×1864647961² = 6953824036922915042, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1864647899 and 1864647908.

It is not an unprimeable number, because it can be changed into a prime (1864647901) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43050 + ... + 74716.

It is an arithmetic number, because the mean of its divisors is an integer number (130820508).

Almost surely, 2^1864647961 is an apocalyptic number.

1864647961 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1864647961 is a deficient number, since it is larger than the sum of its proper divisors (228480167).

1864647961 is a wasteful number, since it uses less digits than its factorization.

1864647961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31832.

The product of its digits is 1741824, while the sum is 52.

The square root of 1864647961 is about 43181.5696912468. The cubic root of 1864647961 is about 1230.8324857631.

The spelling of 1864647961 in words is "one billion, eight hundred sixty-four million, six hundred forty-seven thousand, nine hundred sixty-one".