493721978 has 4 divisors (see below), whose sum is σ = 740582970. Its totient is φ = 246860988.

The previous prime is 493721957. The next prime is 493721989. The reversal of 493721978 is 879127394.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 407918809 + 85803169 = 20197^2 + 9263^2 .

It is a super-2 number, since 2×493721978² = 487522783120464968, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123430493 + ... + 123430496.

Almost surely, 2^493721978 is an apocalyptic number.

493721978 is a deficient number, since it is larger than the sum of its proper divisors (246860992).

493721978 is a wasteful number, since it uses less digits than its factorization.

493721978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246860991.

The product of its digits is 762048, while the sum is 50.

The square root of 493721978 is about 22219.8554900791. The cubic root of 493721978 is about 790.3646119101.

The spelling of 493721978 in words is "four hundred ninety-three million, seven hundred twenty-one thousand, nine hundred seventy-eight".