7278955421 has 4 divisors (see below), whose sum is σ = 7279675200. Its totient is φ = 7278235644.

The previous prime is 7278955417. The next prime is 7278955477. The reversal of 7278955421 is 1245598727.

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: 1245598727 = 149 ⋅8359723.

It is a cyclic number.

It is not a de Polignac number, because 7278955421 - 2² = 7278955417 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 7278955421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7278925421) 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, 344501 + ... + 365018.

It is an arithmetic number, because the mean of its divisors is an integer number (1819918800).

Almost surely, 2^7278955421 is an apocalyptic number.

It is an amenable number.

7278955421 is a deficient number, since it is larger than the sum of its proper divisors (719779).

7278955421 is a wasteful number, since it uses less digits than its factorization.

7278955421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 719778.

The product of its digits is 1411200, while the sum is 50.

The square root of 7278955421 is about 85316.7944838529. The cubic root of 7278955421 is about 1938.0115152306.

The spelling of 7278955421 in words is "seven billion, two hundred seventy-eight million, nine hundred fifty-five thousand, four hundred twenty-one".