20629978 has 8 divisors (see below), whose sum is σ = 30979872. Its totient is φ = 10303356.

The previous prime is 20629969. The next prime is 20629997. The reversal of 20629978 is 87992602.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3400 + ... + 7267.

It is an arithmetic number, because the mean of its divisors is an integer number (3872484).

Almost surely, 2^20629978 is an apocalyptic number.

20629978 is a deficient number, since it is larger than the sum of its proper divisors (10349894).

20629978 is a wasteful number, since it uses less digits than its factorization.

20629978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11636.

The product of its (nonzero) digits is 108864, while the sum is 43.

The square root of 20629978 is about 4542.0235578429. The cubic root of 20629978 is about 274.2623891737.

The spelling of 20629978 in words is "twenty million, six hundred twenty-nine thousand, nine hundred seventy-eight".