1951978 has 16 divisors (see below), whose sum is σ = 3397824. Its totient is φ = 823680.

The previous prime is 1951967. The next prime is 1951993. The reversal of 1951978 is 8791591.

It is a happy number.

It is a super-2 number, since 2×1951978² = 7620436224968, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1951978.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 103 + ... + 1978.

It is an arithmetic number, because the mean of its divisors is an integer number (212364).

2^1951978 is an apocalyptic number.

1951978 is a deficient number, since it is larger than the sum of its proper divisors (1445846).

1951978 is a wasteful number, since it uses less digits than its factorization.

1951978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2157.

The product of its digits is 22680, while the sum is 40.

The square root of 1951978 is about 1397.1320624766. The cubic root of 1951978 is about 124.9755258751.

The spelling of 1951978 in words is "one million, nine hundred fifty-one thousand, nine hundred seventy-eight".