1978923290 has 8 divisors (see below), whose sum is σ = 3562061940. Its totient is φ = 791569312.

The previous prime is 1978923269. The next prime is 1978923329. The reversal of 1978923290 is 923298791.

It can be written as a sum of positive squares in 2 ways, for example, as 1967720881 + 11202409 = 44359^2 + 3347^2 .

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

It is a super-2 number, since 2×1978923290² = 7832274775408848200, which contains 22 as substring.

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, 98946155 + ... + 98946174.

Almost surely, 2^1978923290 is an apocalyptic number.

1978923290 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1978923290 is a deficient number, since it is larger than the sum of its proper divisors (1583138650).

1978923290 is a wasteful number, since it uses less digits than its factorization.

1978923290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197892336.

The product of its (nonzero) digits is 489888, while the sum is 50.

The square root of 1978923290 is about 44485.0906484409. The cubic root of 1978923290 is about 1255.4795794676.

The spelling of 1978923290 in words is "one billion, nine hundred seventy-eight million, nine hundred twenty-three thousand, two hundred ninety".