2661956478 has 12 divisors (see below), whose sum is σ = 5767572408. Its totient is φ = 887318820.

The previous prime is 2661956467. The next prime is 2661956489. The reversal of 2661956478 is 8746591662.

2661956478 is a `hidden beast` number, since 2 + 6 + 6 + 1 + 9 + 564 + 78 = 666.

It is an interprime number because it is at equal distance from previous prime (2661956467) and next prime (2661956489).

It is a super-3 number, since 3×2661956478³ (a number of 29 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 73943218 + ... + 73943253.

It is an arithmetic number, because the mean of its divisors is an integer number (480631034).

Almost surely, 2^2661956478 is an apocalyptic number.

2661956478 is an abundant number, since it is smaller than the sum of its proper divisors (3105615930).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2661956478 is a wasteful number, since it uses less digits than its factorization.

2661956478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147886479 (or 147886476 counting only the distinct ones).

The product of its digits is 4354560, while the sum is 54.

The square root of 2661956478 is about 51594.1515871712. The cubic root of 2661956478 is about 1385.9056019115.

The spelling of 2661956478 in words is "two billion, six hundred sixty-one million, nine hundred fifty-six thousand, four hundred seventy-eight".