2778621951 has 16 divisors (see below), whose sum is σ = 4267433984. Its totient is φ = 1575280224.

The previous prime is 2778621941. The next prime is 2778621961. The reversal of 2778621951 is 1591268772.

It is an interprime number because it is at equal distance from previous prime (2778621941) and next prime (2778621961).

It is not a de Polignac number, because 2778621951 - 2⁷ = 2778621823 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2778621951.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2778621941) 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, 518260 + ... + 523593.

It is an arithmetic number, because the mean of its divisors is an integer number (266714624).

Almost surely, 2^2778621951 is an apocalyptic number.

2778621951 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

2778621951 is a deficient number, since it is larger than the sum of its proper divisors (1488812033).

2778621951 is a wasteful number, since it uses less digits than its factorization.

2778621951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1041990.

The product of its digits is 423360, while the sum is 48.

The square root of 2778621951 is about 52712.6355914784. The cubic root of 2778621951 is about 1405.8634950675.

The spelling of 2778621951 in words is "two billion, seven hundred seventy-eight million, six hundred twenty-one thousand, nine hundred fifty-one".