30679978 has 20 divisors (see below), whose sum is σ = 53695170. Its totient is φ = 13146504.

The previous prime is 30679973. The next prime is 30679997. The reversal of 30679978 is 87997603.

It can be written as a sum of positive squares in only one way, i.e., 30658369 + 21609 = 5537^2 + 147^2 .

It is a super-2 number, since 2×30679978² = 1882522100160968, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (30679973) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1608 + ... + 7996.

Almost surely, 2^30679978 is an apocalyptic number.

30679978 is a deficient number, since it is larger than the sum of its proper divisors (23015192).

30679978 is an frugal number, since it uses more digits than its factorization.

30679978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6419 (or 6398 counting only the distinct ones).

The product of its (nonzero) digits is 571536, while the sum is 49.

The square root of 30679978 is about 5538.9509837152. The cubic root of 30679978 is about 313.0533445198.

The spelling of 30679978 in words is "thirty million, six hundred seventy-nine thousand, nine hundred seventy-eight".