1978657026 has 32 divisors (see below), whose sum is σ = 4090065408. Its totient is φ = 637480320.

The previous prime is 1978657019. The next prime is 1978657033. The reversal of 1978657026 is 6207568791.

It is an interprime number because it is at equal distance from previous prime (1978657019) and next prime (1978657033).

It is a self number, because there is not a number n which added to its sum of digits gives 1978657026.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 153196 + ... + 165608.

It is an arithmetic number, because the mean of its divisors is an integer number (127814544).

Almost surely, 2^1978657026 is an apocalyptic number.

1978657026 is an abundant number, since it is smaller than the sum of its proper divisors (2111408382).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1978657026 is a wasteful number, since it uses less digits than its factorization.

1978657026 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13306.

The product of its (nonzero) digits is 1270080, while the sum is 51.

The square root of 1978657026 is about 44482.0978147389. The cubic root of 1978657026 is about 1255.4232687101.

The spelling of 1978657026 in words is "one billion, nine hundred seventy-eight million, six hundred fifty-seven thousand, twenty-six".